So, excited about getting back into this, but I have a few questions...

Haven't played BG in over a decade and never was that into modding... how difficult is it? I saw people talking about making their own kits and didn't know if this was an integrated feature or a mod.

I was trying to figure out what kind of character I wanted to play, straight/multi/dual but got frustrated. I like the kits, but you can't multiclass with kits. OK, so that leaves dual-classing, but a) I dislike dual-classing and b) that leaves me with only 1 kit and 1 vanilla class. I realized what I want in the end is the ability to multiclass with kits - a desire in which I doubt I am alone.

I understand, flavor-wise and AD&D-wise, why the rules are such as they are in this regard. BUT, subjectively, this directly detracts from my enjoyment of the game, and, if I have the ability to correct this without breaking the game, then I would like to do so.

tl;dr - Is there a way to enable multi-class characters to use kits? (ala berserker/swashbuckler or enchanter/jester)?

Possibly relevant: I am an electrical engineer who has programmed videogames before.