re "soloing"
i have a few non-jazz strategies that i think have helped me with "jazz" soloing:
- improvise a folk song or learn a folk song's melody and then improvise on that (consider charlie haden)
- learn a movement from a bach cello suite and improvise on its motives/ideas in between sections (before repeats or a obvious cadences). i knew the fourth suite pretty well, so i' do the courante, play the first section, improvise, play the repeat, improvise, play the second section, improvise, etc.
- play a completely free melody (slow is better/harder, ime)
- improvise "it the style of" a genre or a motive that you like (i've done mozart, dejent, little ditties i've made rhythmic cells, etc.)
- play "emotions" (happy, sad, etc.)
imo, this get you into playing lines and gestures and deepens how you hear "on the instrument." doing it away from chord changes will help when you get to the changes.
fwiw, for jazz harmony, one thing i've done is steal liberally from parker (and other) tunes' melodies and analyzed how they work over the changes. (i'm not big on learning other people's solos, for good or bad)