Hi,
#1. We use 2 criteria to evaluate: Price from and Rating: https://prnt.sc/wVp9hgydz2Ir
However, both of these criteria you do not use, do not add the price of the booking object and also have no rating. So these arrangements with your Booking object are meaningless.
#2. I fixed this issue, please recheck.
#3. No, only customizations written directly into the main-theme will be lost when you update the theme.
Currently I make customizations in your child-theme and database, so updating the theme does not affect these configs.