I've been composing a song, using the chord progression Am - G#° - Dm7/A - E (i - VII - iv - V), that is using the Harmonic minor scale.

The song has some melodies, that appear in different parts. The melodies are following the harmonic minor scale, but sometimes, I use G natural instead of G#.

The melodies that use G natural sound good to me, but I don't really know if this relationship between the two scales is correct practice.

Can I mix natural minor scale and harmonic minor scale in the same song?

Can I play G natural in a G#° chord?

EDIT: This is the song:

Thanks a lot for the help!