Pretty good, the bits that don't sound too good are where you aren't landing on a chord tone, paying attention to the chords you are playing over and what notes make those chords will help you with your note choices.
Yes
These two bits of advice from Poster Boy and Alex are crucial.. I'm always telling people to try and avoid landing on a chord change with an 'in between' note.. by that I mean you almost get caught in the middle of looking for the right note. I know you were just jamming and when we're jamming we all do it but this is very useful to bear in mind when you construct a solo. Make it desicive, not meandering
Nice job. Just keep trying to come up with melodic statements and emphasize strong chord tones as was stated above. For G minor, Bb, D and F are the strong tones as they are the minor 3rd, 5th and 7th.