...yet he's a reasonable friend, and finding another drummer will take time...
the problem: he CANNOT play anything even vaguely tricky cover wise and says that "playing covers is impossible because that means I have to be as good as the pros".
THEN, when we make original material, he has one drum beat, which doesn't vary and has no fills or anything to lead to a change in tempo to lead to a chorus or bridge.
Should he stay or should he move his enormous fat ass?