#3
It's very likely indeed a female of
Geomyza balachowskyi. However I can't entirely rule out
G. hackmani. In that species the abdomen is normaly much darker (but sometime banded like in
G. balachowskyi). Also the post-scutellum is normally darker in
G. hackmani (but exceptions are known.
#5
I've never seen
Geomyza majuscula with a banded abdomen. But the wing markings in
G. majuscula are more similar to those of
G. tripunctata.
G. martineki is more similar to
G. balachowskyi/G. hackmani. But also for this species (
G. martineki) I have never seen specimens with a banded abdomen.