For motel with catering I think it should be possible to achieve with the university or highschool cafeteria and the community recreation center or community space lot types.
Pianists and entertainers don't spawn automatically on restaurant lots, but they do on lounge lot type. You could set-up your restaurant like usual, include a bar and everything else required also for lounge and when you want an entertainer without paying for them you could play it as a lounge. You can order quite a lot of dishes from the bar too. Not sure why your restaurant doesn't spawn a bartender, could be a mod conflict if you play with CC and mods.