I'd add Hollywood Squares to the "two more stars" pile, though I'd do it where I'd allow the announcer to take the place of one of the stars for each show, with a total of ten different stars playing for charity each week.
Celebrity Newlywed Game would be interesting to watch, with points being multiplied by a certain amount and going to charity.
I'm not sure if Name That Tune ever had a celebrity edition, but it would truly be interesting how much your favorite singer knows about certain genres/songs compared to what many fans think. For instance, a rapper would probably fare poorly with country songs, Billie Ellish couldn't name any Motown classics, while Bruce Springsteen probably couldn't name 21st century tunes. In addition to charity, I'd also play for tickets/VIP experiences for contest entrants, where if the winner wins the Golden Medley, a larger amount of sweepstakes winners would be presented, and could even include fan memorabilia as well.