I'm not a caterer...and maybe I missed reading it, but should the issue of "leftovers" be addressed? Who owns the leftovers? If the customer owns them...there is a chance they could hold them at an improper temp for hours after you left the premises...folks could get sick. It would probably be best to explain up front that temperature sensitive products that are not consumed while you are in control, will LEAVE with you. You'd have to smooth it over so they didn't think you were somehow going to resale or give the product to your personal friends, etc... maybe go with "I'm trained/certified to provide a professional service to you and your guests, please understand that to honor my promise of professional service it is necessary for me to package up and remove leftovers"...maybe promise to donate leftover meat items to a local animal shelter (if the shelter would accept it?). You could also tell your customer, if he or she wishes, you could call the guests up for "seconds" 30 minutes before the end of your scheduled gig? Just throwing stuff out there...
UDS x 2...now they're reproducing!