2) May be, but QMC2's (my) decision to do it the custom artwork way was way earlier than the latest MAME changes... and I don't care for the internal UI (not because it's bad but because it's not QMC2 related).

6) I think that 2) answers it.

7) Yes, I remember, and your post from that time was one reason why I added a Windows-specific option. But regarding usual placement of binaries and data, you're wrong. Anyway, I told you the solution for your specific use case a few posts back.

A mind is like a parachute. It doesn't work unless it's open. [Frank Zappa]