Sure, there will be some hitches, as are illustrated in the OP. Band does Song A in a different key then was learned. Band adds extended solo to Song B. Band doubles up the chorus on Song C. Thats to be expected, IMO, if youre playing 35-90 new songs with a band that youve never rehearsed with. It seems the band that the OP is referencing is also aware of that, seeing as how theyve given him a second paying gig only a week later.
I see what your saying, but your still changing the rules.
I am not sure what part of 90 new songs (not those you already knew) played with no mistakes (no cheat sheets), at a live gig and no prior rehearsal everyone is not getting.
With all respect guys, it can't be done.