So I've played this game many many times but hadn't actually finished, until yesterday. I had a game as a dwarf gun techie and got to level 35 before the poor choice of followers made the game so unbearably frustrating that I decided to start over.
The next character was an elf good diplomatic mage and I enjoyed him immensely. I want to play again because I really just wanted to get the story out of the way with in the previous game so now I'll dedicate more time to exploration.

I played using the Unofficial patch, the follower leveling editor and the high res mod.

I have a couple of questions though:
1) Are there any other addons that I should install? What about the high res town maps?

2) Constitution. From what I've been reading around, people have been saying that Con should be raised to 15 but no higher for max regeneration rate. I chugged a fair amount of mana pots in my previous game because my Con was only about 8. How much of a difference will having 15 make? I would obviously use the +4 Con amulet in this case.

3) Is it possible to complete the Altars of the Gods quest without really progressing with the storyline? I.e. getting to Vendingroth etc (spelling?!).

4) How much gameplay does playing evil give? Is it possible to essentially shoot first and ask questions later using the Raise Ghost or whatever spell? How important would Persuasion be?

5) What does technical aptitude give you? Or does it only mean that you cannot shop in mage stores and high magic resistance?

6) What companions for an evil character? Will Sogg stay with you?

7) In terms of companions, I botched Vigil's leveling scheme and had him & Sogg max out Melee, Dodge, Dex & Str. After that, I didn't really know what to do so Sogg maxed out Lockpicking as well. Is it possible to have them carry out any other function? They were so powerful that having pumped the rest of their skill points into health would have been an utter waste. Is it possible to train your followers (Apprentice, Expert, Master) without the Educator background?

Thank you.
I have lots more questions but I cannot remember them all right now >.<

I only know the answer to two of these: I would definitely use the high-res townmaps, as they look much nicer. Doubly true if you are also using the high res mod. As for other addons, many people like the level cap remover but I've never used it myself. I think it's a matter of personal taste -- I like having a limit on my leveling points because it means my character will never be able to do everything. But some like to keep it going after level 50. Technical aptitude lets you use tech items better. Guns, grenades, weapons and armor that you make with the smithing skill, etc. These items work poorly for a mage but quite well for one with tech aptitude. It will also increase magical resistance. Negatives are that magic items won't really work for you (their enchantments essentially don't work) and magic healing potions will work poorly for you. Instead, you need to use tech healing items in the form of salves. Also, if you have a high tech aptitude, even positive spells won't work on you, like if Virgil is trying to heal you. A tech character will likely want to take other tech-aligned followers rather than Virgil. Generally people consider tech characters to be harder to play, but I think they're a lot of fun.

Thanks for your reply.
Actually, I did use the level cap remover, forgot to mention it though. I finished the game when I was 50 though heh. Didn't really go to many "dungeons" in that one.

As for question 5, I was really hoping to get more specific information. I've played many tech characters before (as I mentioned, I got one to 35 earlier as well) so I know the basics, but I'm trying to get more specific information.
What do you mean when you say that guns work better? Or axes?
Essentially, if I'm using a gun, what difference does it make if my aptitude is 0, or 100 tech? Is there a difference?

I forget the exact numbers, but I think that having low tech aptitude means a high chance of critical failures when using items like guns. If you have some tech items, when you select one you will see some info in the box at the bottom of the screen. One of the numbers there should be something like "chance of critical failure". That number goes down the higher your tech aptitude is. Notice that this is an EXTRA chance for critical faiulre... even if it reads zero, you might still have critical failures if you have low firearms skill or similar. Some of the earlier tech items may have this number reduced to 0 even if you tech aptitude isn't that high, but the more powerful ones need higher tech aptitude before it's reduced to 0.

Similarly, magical items will display a number that reads something like "percentage of magical energy" which indicates how well the enchantment is working for you. If a sword is enchanted with 100 additional fire damage, but the percentage value you see is only 50%, then when you use the item you'll only get 50 fire damage. A high magical aptitude will raise the percentage, a high tech aptitude will lower it. So tech players won't find magical items to be very useful.

A high tech aptitude also means you'll get more health restored when you use tech healing items. The higher the aptitude, the more healing you get. The opposite is true with magical healing items. And as I said before, magical spells directed at you will fail a lot, including healing spells.

If anyone else has some hard numbers, please post.

That makes sense - thanks a lot. Might actually start the next playthrough now!

I am not sure about Sogg although high enough persuasion and charisma should make everybody stay. I even managed to get Z'an into my all good party. I think Sogg does not have an alignment, just like Dog, Waromon or Jayna Styles or some others.

To answer the other part of your question: Z'an (T'sen-Ang) is a nice companion for an evil party. Another mage is Geoffrey in Ashbury, although if you only want to have one mage I'd go for Z'an as she is one of the most interesting NPCs for me. Torian (Ancient Temple) also comes to mind; he is quite a capable melee fighter and a nice replacement for Chukka, for example. And in Dernholm's pit there is this one dude with the hobbit-like name... Tollo or some such. I can't comment on this guy.

Not as far as I know. You can stop picking up blessings anywhere you want to in the chain, though. Or push for Vendigroth ASAP and then backtrack to pick up unfinished quests. I don't think so. Having topped-out melee companions as meat shields was the main reason I took Educator. :) Going neutral on the tech-magic meter is also a workable strategy, by the way---unless you really wanted to solo the game. With companions it's fine to be middle-of-the-road. The only one I took through the whole game was Electric Light, because I hated time-limit torches.

Thanks for the answers guys.