I've been playing to Audiences for 30 years I do not regard my self as good, I enjoy what I do and I suppose that shows. I,ve been getting paid for 25 years I still do quite a few freebies. What I think I'm trying to say love is that you are no judge of how good or bad you are, if people ask you to play they must think you are good enough! and if so then you must be worth paying.so there is no problem is there.

TAKE THE MONEY!!
As for Q2 Just do the Best you can thats all any of us do.
Q3 Sing the songs YOU LIKE to sing Covers are fine most audiences like a healthy dose of songs they already know. Too much new stuff soon bores them to tears.

Good Luck and enjoy youreself

Graham (Guernsey)