Yes, Q7 is D7. The EXP pins are audio in/out. /G is output enable, /E is chip enable. CHR /WR is only used with CHR-RAM, can't do anything with that if you're using ROM.
On the CHR side, CHR /RD would be connected to output enable, and usually CHR /A13 would be connected to chip enable.
That pin 44 is what I call PRG /CE, it will be active (low) whenever the NES is accessing memory at $8000-$FFFF. So you'll probably want that connected to the /CE pin of your PRG-ROM.