I've just started to run this game, and i noticed i have some characters from the first game, I was wondering if its okay to import them for any%? Also is going into multiplayer to take an item from one character to sell for gold on the run?

Importing wouldn't be allowed, since it requires previous data. MP mode is interesting idea, how's it work? Do you need the adapter thing? I've never tried.

Basically I'm trying to circumvent the need for getting gold for potions and gear during the run if the drops aren't great. For the Multiplayer thing, its a bit of a stretch for something that may not be needed. How I've tried, you would start a 2 player game with a second controller, the second character imported being a higher level with extra gear that can be sold for gold. Drop that gear for the first character (would be the run character) sell it and then save. Then start a new game and import the run character with the gold needed for the run. and I would assume that the run would start when you make the multiplayer game rather then the actual run.

Also on a side note, what is the possibility of having different categories for different classes? From what I see, they all would have different ways of approaching the run.

I'd still say no to any importing, since it's ng+ at that point. If you can do the MP thing with two new characters, then go for it though. As for categories, I can add variables for each player class, otherwise it'd get a bit too crowded.