I think it would be fairest for Johnny to come back, but, much as I like him I think he'd be out again almost straight away.
In fact, anyone coming back is going to have a last minute cobbled together performance which didn;t do the Risk any fvours when they had to "re-form"!

It's Modest Management and yes all the finalists are under contract until after the tour. It's why even Nu Vibe who got voted out first were able to get gigs until Ashford left as Modest arrange them. All of the eliminated contestants do the obligatory gigs at GAY, Nightingales etc. as far as I know.