MrRight: This game has got me back into RPG's after a long hiatus but I have some general questions.
How long would an average playthrough take assuming I do every quest I come across using minimal spoilers? Or even how far into the game am I if I'm about to leave Tarant?
I chose a pre-designed character (Muck-Evil Eye) and just let the points distibute based on this character. Will this hinder me much?
Will I hit a point in this game where I'll need to choose between characters? (such as deciding whether to ditch Virgil or not?)
I'm bad at estimating length in terms of number of hours, but the game is pretty long. One issue is that the side-quests you do depend on your character; and evil character could get different quests offered than a good character, and other quests are related to your character's strengths. Someone else please jump in and give a better length estimate! I can say that if you're only just leaving Tarant you're still at the beginning of the game.
As for using the pre-made character's auto-leveling, it depends on whether you're concerned about your character being primarily EFFECTIVE (good at the game) or if you're more interested in roleplay. The auto-leveling will probably make you reasonably effective but not quite as effective as you'd be distributing points yourself, but the auto-leveling usually fits really well with the character in terms of roleplaying. It can be really fun to play Arcanum when you're not just trying to be the most effective character possible but are instead trying out different skills and such. Also, if you ever have a problem with the auto-leveling, I think you can turn it off at any time, or even switch it to a different auto-leveling scheme.
As for choosing between characters, there are many NPC characters that can be recruited in the game, but your character will only be able to bring a certain number with them at one time. This is based off of your charisma I believe; higher charisma means you can recruit more people. Also many NPCs will only want to travel with people of certain alignments (good/evil, based off of how you've acted during the game) or will only work with technology-focused or magic-focused characters. So if you are at your follower limit, you will sometimes have to choose which followers you want to travel with you and which you want to leave behind. But since the depth of choices offered to you is one of the main strengths of the game, many players see this as a plus. Play through with one set of followers, then start a new character and try a different group.
Hope that helps!