Hi Dana,
personal i find many things are "personal choices", but there are also things we know for sure and that is:
1) some weapons require an amount of strength, dexterity or intelligence (points).
2)
Strength increased your melee damage + increased your melee resistance + Conditioned Body!
And the same with
Dexterity > ranged damage + resistance + Heightened Reflexes
Intelligence > magic damage + magic resistance + Indom. Will
3) there are many weapons and equipment that give extra Hitpoints or Manapoints or points in Vitality or Spirit...
4) there are also charms and enchantments
5) look at your amount of HP and Mana after leveling up!! Without putting a point in vitality or spirit, each level-up give you (if I'm right) + 4 points in both stats!
6) since you can change all skills after having your Battle Tower, you can choose skills you like to use in the beginning of the game and later on by your Trainer you can undo all skills and choose the one you like. For example : if you have skillpoints over and you wish to "loot" each chest, barrel, crate... you can put all 5 points in "encumbrance" so you can wearing much more! If you have your Battle Chest, you don't need this skill anymore.
What
I find some basic skills in the baginning? (whatever you choose: Warrior, Mage or Ranger)
Wirlwind is for me good for only 1 point in it, just so I can quickly open barrels, crats etc or do 1 wirlwind if to many enemies surrounded me! But I used also most of the time my bow to open barrels etc (so now on my second playround I put NO points in Wirlwind)

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Magic Missile is fun in combination with Destruction and Confusion (both passiv skills that increased damage and give you a littel more time (confusion)... and Magic Missile used not so many mana and have a short cooldown period. BUT: do not so much damage and is not so fast like fireball or Magic Blast! This last one I find realy powerful, but have a longer cooldownperiod and used more mana, but there are potions enough (to find or make).
I would not go for a pure warrior (or ranger), but a combination of more than one class (skills)! Pure Mage maybe is possible? But for me a littel bit too borring always using magic... because I find it funny to slay enemies also with a melee weapon

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Lockpick I put little by little 5 points in.
Personal I find a Bow a good thing to have in Divinity II !! Great, together with the skill Poison Arrow (1 or 2 points) + Ranger Stealth, fun!
I buy now (second play) totally NO gear from traders! All gear I wearing I find from loot or is given after a quest! and there is many gear to find etc! So I sell many goods and have so much gold now

I can later on maybe buy a strong weapon or enchantmentformula or other expensive gem... and change my skills in Battle Tower, if I wish more than one time

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