I always asked the following -
What is the head count (also include that you will ask this again the week of the event). You don't want people to say 100 when there is only 50 that show. Make sure they understand that they will pay at least the per person price on the last head count, that they provide.
Serving? Do I serve or will serve yourself.
Left overs - do they keep or you take back.
How long will the food sit out? you do not want people going back for cole slaw after it set out for 2 hours, and they will.
Location of the event - does has tables, electricity (if you are using warmers), and water.
Exact time of serving - (sometimes they need you to set up at 11:00 but do not want to serve until the guest of honor comes at Noon).
Untensils - who is providing them
and biggest of them all.
Payment - When do you expect to be paid.
Lit & Loaded BBQ
I remember a day when I hated pellets -
2 pellet cookers latter!
CBJ - love judging
KCBS - member for 4 years
Super fast - BLUE