Being able to play other music doesn't make you bad. Its focusing on those songs instead of doing your own thing that's wrong. And uh buddy, hate to break it to you, but improv is old news to me. Firstoff, four years of experience with a sax. Secondly, the same four years of experience with a sax were with a Tenor, THE instrument for Jazz improv. We're talking John Coltrane's weapon of choice. I actually did my first of two reasearch papers that I have to write to graduate HS on John Coltrane, his life, and his styles of Improv. And I do know the circle of fifths, all the minor scales, and 10 relative pitch patterns that I'm using right now. And the high school jazz band is amazing. So trust me, I know improv.
(Musical) w00t