Newcastle Upon Tyne
If I have a finished wonder, does it even count as a progress card in the end if progress cards is a winning criteria?
The rules state that unbuilt wonders "still count as a Progress Card when scoring that criteria". The clear implication of that "still" is that they count as a Progress Card built or not. If, once built, the card did NOT count then this would have to be explicitly stated in the rules. It isn't, so a wonder counts as one progress card towards endgame conditions and victory criteria whether built or not IMHO.