Survivor is probably the most challenging class.

differences between classes (minor spoilers)

Early Starter Tips (NON-Spoiler Version) (contains much of the information in the above topic)

Did you loot Aleroth? Are you checking with George for equipment upgrades periodically, etc? You should be able to collect enough crappy loot to trade with the healers for potions and gold, and if you are lucky maybe something else. Stash higher value items until you get to better merchants later in the game.

The Aleroth catacombs can be difficult, but you can leave Aleroth and level up outside, if you wish. The orcs to the north, east and west are weaker and in smaller groups than if you go too far south. Don't forget to return to the catacombs, though; if you progress too far into the main plot quests, Mardaneous will be cured without your help and a couple other quests there will also progress without you if not yet completed, so you would miss the XP and rewards.
A bow and Poison Weapon can help; it would be effective against the orcs outside, though somewhat less with undead and spiders in the catacombs. The Survivor's Curse skill can be cast repeatedly on a target to greatly lower their resistances, though, so any poison or elemental damage will be more effective, or skills like Polymorph that can be resisted with spiritual resistance can apply when they wouldn't normally.

As the game progresses, it tends to get easier.

The very beginning and end of the game are heavy on the hack and slash (much of it at the end can by bypassed). After the catacombs, once you head south and get into the farmlands, there is a much better mix of exportation, quests, NPC interaction and combat.

The topic sorta new, got a quick question contains some information on playing survivors.

Free skills, and spell books you can buy

Divine Divinity Character Development FAQ

Actually, Spear Expertise is over-powered early game, though it isn't a very publicized bug. Specifically, throwing a spear is suppose to do 60% of the melee damage at level 1, but it actually does 60 damage. Level 5 should do 100% but does 100 (not much less than a late game one handed sword).

Warriors are the most straightforward class to play, and the game is fairly biased towards swords when it comes to potentially good weapons consistently in the game.

In the old Larian forum there was a topic called 'Way of the Sniper', with a guide to build a reportedly very effective survivor based archer. Much of the information from there was repeated in the topic in the current forum: 'Archery as a warrior - my thoughts'.
http://www.larian.com/forums/ubbthreads.php?ubb=showflat&Number=130132&an=

Another under appreciated spell is Burning Wall; it is good for crowd control or single targets, and can be used defensively as well as offensively. The best use with single targets requires good timing and coordination, though, as you need to activate the spell and make a (preferably tight) circle around the target.

Playing a warrior in my first game, I found a spell book in Mardaneus' house (random find in bookcase), which was the only way I was able to defeat a particular opponent at the bottom of the catacombs (it was an optional side room, though, so I could have come back later, with better equipment, etc). I only used it once more after that, to help with the first large group of orcs south of Aleroth.
Later I tried someone else's save (they ran into a problem with a cutscene later, due to never opening the catacombs), and they were playing a mage that pretty much only had level 5 Burning Wall, a couple other spells from quest rewards and a spoon equipped as a weapon (it didn't look like they even bought many spell books).

For quite a while after playing DD it was what I compared other games to in terms of world interactivity. Quest design was decent for the time, as well, and the graphics still hold up, considering.
I can't remember the name, but I tried the demo for the latest and greatest ARPG a year or two after DD, and most of the chests were just painted background. That wasn't a big deal, but after a bit of exploring I found a room with a large pentagram painted in blood, with candles at each point... unfortunately, everything was just background, and the candles could not be lit. I quit then, since there wasn't anything unique or compelling about the combat (I'm not really a big fan of pure hack and slash).