I haven't played the game enough to safely answer all your questions (just a few hours in) but from what I have seen:
- geometry and chest contents are the same each time
- enemies and their drops ARE randomized and keep respawning (unless enemies just really move around a lot and end up in places you have already cleared but I don't think that's the case)
- it is indeed impossible to max out all stats, you get two character points per level up to to level 15 and one per level up to level 30
- from what I understand different skills such as "long weapons" or "hand to hand combat" have their individual experience points and levels that are entirely unrelated to the character's own experience and attributes and improve by frequent use of the skill (that's what the manual says but I don't even know how to check these skills in-game)

What I completely can't comment on yet is if dialogue choices have any impact on anything other than, well, slightly different dialogue. Anyway, as far as I can tell the game doesn't have much replayability and you beat it once for the story.

Curiously the game also has a multiplayer mode where you apparently develop your character over many sessions but if I understand correctly it's PvP only.

I know now that I can't max out my skills in Revenant, that's clear to me now. I also learned that you cant get everything when you play, like if you put skills points to melee, you can't pick the locks on chests and such. I was told that there isn't much replayability with Revenant, but what if you play the game with skill points to melee - can you play the game again and the next time put skill points to magic, and play again with points to lock picks, etc? It's a different strategy each time. Would that work? Or would it still be mundane because everything (enemies, loot, etc) are still the same?

I've just finished the game and can answer some of these:

-Replayability is slim to none since choosing different dialogue options doesn't change anything in the story.
-To answer Gavindale's question, sure you could do that, I guess, but all that would change is how you deal damage to enemies. Sword remains your best option but I suppose you could go with another weapon type if you like longer fights.
-Re: lockpicking, you don't get the opportunity to level the skill deliberately, you get given the lockpicks early in the game and there is a limited number of locked chests you can open with them. None contain anything essential, either.
-You definitely can't max all stats: you get a total of 45 points to distribute and that's it, and that's only if you reach level 30 (which will require a bit of grinding). I was level 28 when I finished and I simply followed the story.
-Skills are improved through use, but only if you perform the killing blow with that skill. For example you can wail on an enemy with hand-to-hand skills, but if you switch to a sword and kill it with that at the last second, only your sword skill will increase.
-To check skill progress: Click the quill icon, then select Skills where you see the words "Stats/Skills".

Unfortunately for Revenant, the game's budget was slashed thanks to Dai-ka-fucking-tana screwing the pooch and Eidos attempting to plug their money leak by reining in the budgets of their other in-development games.

It's really a pity, Revenant had a lot of potential and deserved to at least be completed properly. As it stands, the last quarter of the game is a mess and the ending is... ugh.

Holy hell, what a necro! I had totally forgotten that such a game even existed! I shit you not, the title didn't ring a bell and I had to stare really hard at some screenshots before *any* memories of this game started getting back to me, lol.