charbon: I played as a Priest as well on my 1st playthrough. I'd recommend putting some points in speed, but that goes for any class I think, because even when running the character is pretty slow. And it will be useful to get the hell out when things become hairy. Constitution is probably the most important stat after int, as enemy mages can deal A LOT of damages. I can't say anything about dexterity, as I almost never used weapons (a little at first to break locked doors and chests, but almost never in combat), let alone ranged ones. By the time you reach Act 3 you'll probably have at least 3 stats maxed, and all of them by the end of the game so it's really not THAT important overall. Just concentrate on int/con/speed.

About the priests skills, Holy Aura is a good choice, as is Mana restoration in the beginning (you won't have much use for stamina potions so you can use them as secondary mana potions). Spiritual Insight, I did max it but I admit I have no fucking clue what it does exactly. I never noticed any differences wheter it was active or not. Didn't use Alchemy either, as you can buy all sorts of potions and money is only an issue in the first hours of the game. Armor Use, I dunno, you can only rank up this skill once and the armors this will give you access to aren't that much more efficient than the basic ones. Authority is useful as well, but even maxed it won't be enough sometimes and you'll have to click on the same intimidation/begging line over and over again until the NPC speaks. Perception yes, you want to upgrade that as you'll easily be able to detect traps and secrets.

charbon: Spiritual Insight doesn't make your surroundings pitch dark if that's what you're afraid of. Really I have no idea what it's supposed to do. Could be that the skill is just glitched...

Authority doesn't seem to have any effect when casting spells. Almost all enemies do flee when their health gets low, but I don't know if that's related to this skill. I assume that it only works with physical weapons.

charbon: That wouldn't work, because you can't rank up your weapons and armors skills as high as the paladin. Not to mention that the stats are capped at 50 or so, except for intelligence. You can go above the limit with special items though.

charbon: I didn't have much use for this one. I put most of my points in all types of magic, so I had to forget about some other minor skills. I suppose it can be helpful to prevent from being interrupted while casting spells, but you can easily do without as you'll have 2 NPCs to act as baits very early in the beginning, and even a 3rd one in Act 3.

Gazoinks: Speaking of which, where do you get the second NPC? I've got the dog, but I haven't found anyone else willing to join me yet. Also, I thought only Thieves could get more than 2 companions?

PaterAlf: You're definitely wrong there. I play as a paladin and I have four companions at the moment (in the middle of act 3). I think the next one you can get is landsknecht Olfghard after you complete his quest (but you have to pay for him).

charbon: You can also rank up as a priest, but you'll only get 1 companion once you reach the highest rank. In Hillbrandt you can team up with a soldier or a thief (the latter only after a quest if I remember correctly).