? QxQ would've been a lot better.

? costs crucial time as white mounts the final assault.

Perhaps to prevent Bh3 and 1st row queen checks.

Qxd3 Qh6 loses immediately.

all the white pieces vs the black queen.

again to struggle for initiative so white would divide forces. Rd7 or Ra6 might've worked better.

expecting slaughter at g4 I try to protect g7.

! removes one of the defenders of g6, with a tempo.

Without the 7th row black rook there would have been a lot of exchanges at g6 followed by checkmate. Even now, Bxg6 hxg6 Nxg6 Bxg6 Qxg6+ Rg7 fxg7 Qf7 Rf2 wins easily in a few moves.

Mainly to prevent Rxe8 Rxe8 Bxg6 etc.