personally, i think this is one of the worst music recordings in the history of music, but i think that with a few suggestions i could become at least decent at soloing/improv.
You have some pretty good ideas. I think your main focus should be to concentrate on playing cleanly. Practice slowly and try to minimize the buzz noises and little slips.
yeah, it could be cleaned up a little as far as all the fret noise, and work on the timing, and you've got yourself an awesome bass solo...oh yeah, and i think this would sound cool with a drummer!
Clean up your technique a little, and practice with a metronome, and before you know it you will be taking off. Good framework to build. Keep it up!! 
