Is it possible to have tabs on multiple rows in the IM window?
In other words, when the window is small, you have to click the arrows on the side the tabs...I'd personally prefer multiple rows of tabs, so I dont need to click the arrows.
I don't have an answer to your question, but I do think that the tabs being on top is really obnoxious.
Try putting the tabs on the left, I think it makes a lot more sense, and you can fit a lot more without scrolling.
No, that's not possible, it's not something gtk allows. 'Solutions' include putting your tabs on one of the sides as progoth suggests, using aliases for your buddies to make the tabs smaller, widening your conversation window, or limiting the number of conversations in a window to a number that will fit (either by hand or via the extplacement plugin which ships with gaim).