I played about 3/4 of the way through Divine Divinity a year or so ago, and I might start playing again.

I found myself doing whirlwind a lot, double-tapping the spacebar to see if I need a potion, and then chugging as needed. It wasn't pretty, but the potion system is easily spammable and sort of cheap like that, so I exploited it, what with rejuvenation potions becoming highly affordable mid-game.

Have any of you had much luck playing it a little more delicately? Or more fun, for that matter?

Also, I never used magic, but I heard that a lot of skills just plain aren't viable at all long-term. What do you recommend? I got a fighter up to a high enough level where most of the remaining skill points will be fluff, unless I throw in an attack spell for variety. I'm not sure whether I want to do that, or if some other easily-underrated skills should be in the roster instead.

They say hellspikes is the spell you'll be wanting to use late in game as a magic user. You'll have enough mana to use it by then, but also, it ignores resistances so nobody is immune to it. Which apparently becomes a big deal later. I wouldn't know; I'm only maybe 2/3 on my first playthrough and it's as a magic character who uses a bow a lot.

People tend to warn about freeze being resisted a lot, and meteorspike, at high levels. You can put points in curse to help that out, though. But it's not like points grow on trees even if you farm vendors religiously, so I'm using my bow as long as possible instead of putting too many points into offensive magic. I am maxing freeze and slow most likely, though, because even if they are resisted a lot in the late game, when they work, they make a huge difference in the game.

Of course, if you get a frost weapon you might not need freeze as much anymore.

Freeze is really nice, and can make many fights much easier; also, having played through the game several months ago, I don't remember it being THAT much resisted.
If you don't want to invest in (offensive) magic, you could always put points into some Way of the Survivor skills (such as Know Creature or Wisdom); they can turn out to be very useful.

That said, you could save up your skill points a bit. I don't know where you are in the game, so I don't want to spoil it, but after a certain event, the fourth category of the Survivor way opens up, and it contains a number of neat skills.

I was at the point where you have to assemble the council.

I spoilered myself over at GameFaqs, and... wow, that sounds like a huge advantage. And it explains the title of the game! I'll keep this in mind if I ever get that far again... If I remember correctly, I was just starting to not want to spend points anymore.

I never want to spend my points, always hoping for something better, or to discover a book. Until yesterday I had 13 skill points and 27 attribute points saved up. I finally spent 3 skill points on my bow, and it made the game much easier. It may not be the smartest expenditure, but getting through enemies quicker because of the reduced bow speed has made Iona's dungeon less of a chore. But I'm at 34 now with 10 and 27 points left.

Points grow on bookshelves. :P

Not really on-topic, but I felt it deserves to be here...
Vendors restock every time you level up. This means that if you want to "farm" them, you can do so by saving just before you check one's inventory for the first time during your current level, and if (s)he doesn't have anything you want, load the game.
There's one exception from this rule. After that certain point, when the playable area gets restricted to the Wastelands, the only available vendor restocks quite frequently (every few minutes, if I'm not mistaken). He regularly has skill books and very, very useful charms.

Believe me, I have farmed so much that it almost ruined the game for me. You can get a lot of books, but soon enough a lot of them become repeats. And it can take many, many hours whether you get anything or not.

Which some people dig. Diablo 2 fans can do it for months if not years. I'm not sure the average person wants the game to come down to reloading either a bookshelf or a vendor hundreds of times ... then doing it all over again a few minutes later.

It's definitely no equivalent to good things going on trees. Just more generous than the game naturally is, at the cost eventually of a huge chunk of time.

I haven't been to the Wastelands areas yet, but I don't know if the odds are any better there.