Hello everyone!

Is it cheap/cheesey/overpowered/whatever to play a multiplayer game with a few PC characters? What about using characters that completed the game to transfer items or just help out in general?

To me, I consider using multiple player created characters to be fair, especially given the poor (or non-existent) reputation of certain classes among recruitable characters.

On the other hand, importing characters who have beating the game could easily break game balance. If you are looking at a normal playthrough, I would recommend not doing so. For a glitch playthrough, on the other hand, you might find some uses. (How else would you kill the tutorial guy in Baldur's Gate 2's tutorial?)

No.
Yes.

Creating custom characters is perfectly ok in multiplayer, providing the rest of the players are ok with it. As for transferring items, you cannot. If you save a character from BG1 with certain items in their inventory, they will become available in BG2, but there are only two items from a prioritised list, and findable in-game. If you complete BG2 and re-import that character, no items will be transferred at all.

Thanks for the insight. I decided against it because it felt like cheating.

I wasn't talking about manipulation or exploits. The OP has already stated they feel it is cheating, even without doing such things.