Anyone know the exact requirements to pick up followers? I'm using the list on Terra Arcanum, but it seems to be highly inaccurate (their quest descriptions are way off too).

I'm currently level 9 and trying to pick up Magnus - Terra Arcanum says that the only requirement to do that is that I can't be too evil - I'm not evil at all however, and it still won't let me say anything but "Goodbye" or "I'll be off then" to him.

Number of followers is based on your Charisma.

Yeah, I've been all the way down in the basement of the store and have resolved the plotline down there. I did it in a non-violent way. Does that affect Magnus?

My Charisma and number of followers is such that I don't have room for him, but other followers have said that outright to me - that they wanted to join me, but it seemed I have no room. Magnus just says bye.

EDIT: On a sidenote - if I ask a current follower to leave the party, can I pick them up again? Do they return to where I found them or something?

the Charisma of a Character affects his or her ability to persuade others, and also determines the maximum number of Non-playing Characters who will follow him or her willingly
if you hit the c key under derived stats it tells you how many followers u can have. each new follower cost 1 stat more of charisma per follower ie 1 follow. = 1 charisma, 2 foll. = 2 charisma. 3 f =3 etc so its best to save a few stat points now and again dont use them up so fast when you lvl up

If you did the underground quest in a non-violent way then Magnus will not talk to you or join you. ***Spoiler*** That's because they are using his ancestors dead carcasses as labor. Not something he is going to be cool with. If you had killed the Necromancers then he might have spoken to you and joined you.

And yes you can ask a party member to wait and they will stay at that location for certain period of time. Eventually I believe they will leave and go back to where you first met them (not sure on that last part).

Being an apprentice in persuasion actually makes your followers wait longer where you left them.

As for Magnus - I was able to make him join me when I had good reputation of 36 points. He starts with 35 points himself, so your character has to (probably) have a minimum of 35.

As for doing the quest in the building in front of which you meat Magnus - it's recommended to take him along before doing it, partially because of what Painboy mentioned above.

Not sure if I'm too late here, but you need to have 1 point in persuasion in order to recruit Magnus (it opens up dialogue to ask him why he's at Schuyler and Sons and that you have a common interest in the place and should work together). Alignment just needs to be positive as far as I can tell, I was able to get him with about 12 positive alignment.

And as previously mentioned, if you handled the Schuyler encounter peacefully, the next time you talk to him the only option you have is to tell him you did so, which causes him to dislike you. If you do recruit him before the Schuyler encounter it can ONLY be handled violently (but it's worth about 400 gold + loot)

"1 point in persuasion" no i didnt u need charisma check my post above to see how many u need then click c to see how many followers you can have

I was able to pick up Magnun even when I solved the quest in a non-violent way. I just told him what happened and ask him if he would like to join. I have a high beauty though (ladies man perk) but default charisma (8) and no persuasion point.