Reminds me of a common patter in JRPGs, where you fight a boss, then before you have a chance you have to watch a sizeable cutscene. (Note that this includes final bosses; even when there's New Game +, you often still have to watch the entire ending to actually unlock it.) These sorts of things make me worry that there will be a power outage or (if running from optical media) a disk read error before I have a chance to save, which would make me have to fight the boss all over again.

As with most of your questions, I think the only thing that SHOULD be avoided is forcing general rules on every game without context. It heavily depends on the game in question and how it is balanced.

Balancing is difficult, and even if you manage to achieve a decent balance, there will always be players who complain that the game is too hard or too difficult. I think the best thing a game could do is to suggest a "play as intented" difficulty but allow players to customize it to their liking or at least suggest other difficulties with more or less resting restrictions and similar as well. That way it would be clear for all what the original challenge is, but you would be free to ignore it or up the ante.

I do like small challenges, so I'm not averse to doing a few battles without resting in between, but I dislike when it gets too stressful, e.g. when fights get harder and harder and the game gives you no clues as to how long you will still have to go on without resting. I would totally hate it if I had to repeat lenghtier parts with several combats because it turned out, I could not win the last of them anymore due to my party being too weak without rest already. And yes, I'm thinking of a particular example here, namely Knights of the Chalice which combines both extremes: allowing you to rest as often as you want outside of combat, normally, but then shuttting you in in areas with heavy resting restrictions and no further hints.

Balancing individual encounters is easier, and repeating them less frustrating; I don't enjoy it when an RPG become too much of a strategy game (beyond the usual character building). So I guess, tendentially I prefer free resting over serious resting restrictions (or savepoints that require backtracking, to be on the safe side). But like I said, it depends.

But what if the player wants to re-fight the boss? (Maybe the player used too many consumables, or wants another try at stealing items or sparking skills?)

Depends on the game and execution.

Saving:

Preferred - anywhere except during dialogues and battles (except for SRPGs) is best and convenient. Pokemon or Trails in the Sky series does it best here. It gives the user the freedom to play the game however they want. But Trails does it better with multiple save slots in case anyone wants to revisit cutscenes again without having to skim over Youtube videos.

Acceptable - savepoints are also fine as long as they're reasonable scattered generously throughout dungeons and always available in the world map. FFs and Tailes do this. Quicksaves are expected nowadays too.

Unacceptable - only in towns without any autosaves. Tokyo Mirage Sessions (and I believe SMT series too?). There were warp points in dungeons as checkpoints, but getting to them were so difficult combined with a brutal random encounter that chased you meant sometimes you were losing 1-2 hours of progress because of RNG and not carrying escape items. I had to leave dungeons every 30 minutes due to paranoia and it made them very repetitive.

Autosaves are also very convenient, but they should be there in conjunction with manual saves and multiple auto-save slots just in case.

Resting:

Traditionally, easy access to inns, resting spots, etc. with mandatory resting after significant events or timeskips was preferred until I played FF13. Having your HP/MP restored before every battle meant they can be more challenging to offset resource management mechanics. It'd be nice to have the option to choose depending on your playstyle so challenge-runners can do their no inn challenges, but it all depends on execution.

Out of curiosity, are you developing your own game with these topic threads? I find there are lots of veteran RPG opinions to draw from this community compared to others.

I guess I'm too spoiled by multiple save slots so I forget it is noy an option in many games. If you want to replay to fight you had to save before anyway.

Somewhat relevant: in The Witcher 1 autosaves don't overwrite each other. So you can go back to almost any point in your playthrough without even making an effort, but on the other hand if you don't delete them you end up with dozens of them in the save game folder.

I kind of agree with this. I actually prefer it when games are a bit less permissive about saving, as it is more challenging and I find the temptation to save scum can often spoil immersion. They're not RPGs, but I liked the way Dark Forces and AVP handled saving. In DF, you get a certain number of lives to complete the level; in AVP (which I particularly liked), you can save anywhere, but you are limited to a certain number of saves per level (depending on the difficulty setting).

Pausing, OTOH, is something I think games should let you do anywhere, including in cutscenes. That would help with the 'kid-walks-in-with-arm-bitten-off-causing-me-to-miss-important-cutscene' syndrome, but without encouraging save scumming.

Regarding resting: I like my RPGs to be realistic and immersive, so resting should be permitted anywhere it makes sense in the context of the game world. I quite like games that allow you to try to rest even in unsafe areas, but with an increased chance of being disturbed by enemies. That then forces players to have to make a judgement call. It also helps when traveling back to a safe area is not risk-free (one of the issues with widespread access to fast travel). Another way to do it would be to make 'camping rough' provide less healing than sleeping in a warm bed; limit how often you can rest; and make it non-trivial to get back to the safe area. I can't think of many RPGs that stand out as doing the resting really well, tbh.

Of course, in RPGs where your magic points recharge automatically over time, resting is often not even necessary. One of the things that (imo) makes Divinity: Original Sin too easy is that spells recharge fairly quickly, so your healer can fully heal the party after every combat. (the other is that it is too easy to flee combat and teleport back to town whenever you feel like it)

I tend to dislike checkpoints and I prefer saves anytime, anywhere with reasonable exceptions.
For example I'm ok to not be able to save during combat (if combat is quick. If it last 3 hours no....) or in the middle of a cutscene.

Rest: that depends on the game itself.
A mission based sci-fi RPG? Between missions perhaps.
An horror RPG, very fast paced? No rest at all and some other mechanic is needed to restore values.
Generic high-fantasy rpg: make a campsite or rest at a tavern.

Romancing SaGa: Minstrel Song did this before FF13 did.

Granted, in RS: MS, there were a couple resources that didn't recover after each battle (namely character LP and weapon DP), but once you know how things work, it's not hard to get to the point where you can win most normal encounters without using any of those resources. (Tabletop RPG analogy: It would be like playing Dungeons and Dragons 4th Edition and being able to consistently win common encounters without using daily powers, but still using encounter powers. Note that 4e is very different from other editions of that game.)

Reminds me of SaGa 1, where you only get one save slot. While it's nice that you can save anywhere and saving is effectively instant, what's not nice is that it's possible to save in a situation where the only way out is to defeat a boss, but you're not strong enough to defeat that boss. (Yes, this has happened to me.) What doesn't help is that repeating the fight until you get lucky doesn't work because the game's RNG will give the same combat results after every reload (it's perhaps one of the worst RNGs I've seen in a video game).

Interestingly enough, Stranger of Sword City Revisited does something like that on easier difficulty levels: You get a small number of light orbs, which can revive your party in case of a party wipe, and they recover when you return to town. Unfortunately, the same difficulty selection affects the levels of enemies; it would be better if they were separate settings, like the wonderful difficulty settings in Fell Seal: Arbiter's Mark.

Dungeon Master handles resting better than many WRPGs, at least in terms of when you can rest. You can rest at any time, even when engaged in battle (the game's battles are not on a separate screen), but if an enemy attacks you (even if the attack misses I believe), your party will wake up. No "can't rest because the game thinks there's an enemy nearby" mechanic. I also note that resting takes time to heal, which can sometimes be annoying, but it's at least not as bad as Wizardry 6/7.

That brings up another point: It needs to be possible to bring your party back up to full strength in a reasonable amount of time. Wizardry 6/7 fail at that, with resting being very slow and the lack of a healing spell that's decent at higher levels; Pool of Radiance is another offender, where the fastest (in real time) way to heal is to rest for weeks of game time, which is ridiculous. Wizardry 1-5 (excluding 4) are annoying at first with weak healing magic and it being easier to restore spells than HP by resting, but at least you eventually get a full heal spell which makes the problem a non-issue at high levels.

As for the other Wizardries:
Wizardry 8 made HP/SP recovery when resting much faster, to the point where you can recover in a reasonable amount of real time.
Wizardry 4 is different; when you hit a pentagram, you are fully restored; however, your monsters disappear and you need to use the pentagram to summon 3 new groups of monsters to protect you.

I've been saving anywhere pretty much my entire gaming life and have no patience for anything else. Especially now that family demands make it hard to game for long stretches.

Resting is another story though, I love that feeling of being deep in a dungeon with few resources left and having to find a way to finish it. I think a basic resting limit works fine for this though, no need to overthink it. Both Pillars of Eternity and Pathfinder Kingmaker had very limited resting supplies so you could only rest a couple times in dungeons, which was great.

Ok. I haven't played either of those, but they sound interesting.

I haven't played DM, but would like to. Hopefully it will appear on GOG at some point.

Yeah, there is definitely a balance to strike between making resting/replenishing somewhat challenging, but not too difficult.

Now I really have to play SaGa now given how innovative it is by your multiple examples. I personally got turned off by the series because I learned it was a spiritual successor to FF2 and that was, objectively, the worst JRPG I've ever played in my life. Hope SE brings them to GOG someday because I don't want to go back to Steam anymore.

The game should auto-save at all times.

Resting should be allowed everywhere with consequences.

Like some other users who have posted here, I prefer being able to save my progress any time outside of combat, like in Legend of Heroes Trails in the Sky, because I feel that not allowing this makes for some grindy sessions where you aren't playing so much because it's fun but to get to the next save point. With combat in real time, like in Darksiders 1, the game does let you save anywhere(even though some would not consider it to be an RPG; I do) but you can get penalized for not relying on the auto save system of checkpoints, and can find yourself having to repeat puzzles or swarms of enemies, which I didn't care for.