thanks for your response about STDs! I probably will do the same
as for favors: from personal experience as a former banquet waitress, many people leave their favors on the table. I've collected quite a few over the years.
people like food because they eat it right away. I also like the idea of picture frames for placecard holders. Ones that I have received, I use. Also, if someone leaves it you know who to give it to haha, or you can keep it for yourself