Completely agreed on this point. Even if there is no official advantage to being labeled as a donator, having a badge in game or on the forums will provide (in my opinion, unwarranted) psychological weight to your posts and opinions.
I agree with this sentiment in general, but at the end of the day accounting might be more busywork than anything else.
As for the extra money, it's always nice to have a surplus. I would very much like to see this surplus being used for some kind of DDOS protection, or we might want to hop onto another machine with higher capabilities (I'll default this opinion to those that know more about the hardware aspect of the server and servers in general than I do). At the same time, we don't want to starve ourselves if for whatever reason donations dip.