Regarding the need to read music, I'm reminded of the old story about the very famous country music bass player in Nashville, who was asked on arriving at a recording session 'Do you read music?'. The reply? 'Not enough to hurt my playing'.
As with so many things, a search for absolutes and 'ideal' situations seems futile. There are just too many variables; live or recording studio? Music genre? Structured or improvisation? Solo or ensemble? The good news is it seems to be possible to succeed in music with or without the ability to read music. The real determinants seem to be talent, motivation, dedication and a degree of originality.
Incidentally WAV; well done for not mentioning your website in your last post.
Tim