Another omnivore checking in:
I totally understand the allergy issue. I have a sensitivity to onions, or rather, an enzyme in uncooked onions. While in college it was so bad that I couldn't even eat anything with powdered onion in it. Almost *everything* commercially available has powdered onion in it.
I definitely know the (literal and figurative) pain of trying to eat outside my own cooking, and always ask about food restrictions when inviting guests. I'm also a recipie junkie!
For my wedding we asked specifically for a vegetarian dish for a friend of ours and the caterer was happy to oblige, all he needed was to know where she would be sitting. So you may not have to pass on eating at the reception, if the bride and groom know enough in advance to prepare for it.
As for meat-tasting tofu: Theis same friend was born without the enzymes needed to digest meats (both parents are vegan) and is really teed-off about it, so she goes for any meat-tasting tofu she can get.
I think it really does boil down to *thinking* about diet. Thinking to ask about restrictions, and thinking to provide a host/hostess with options for the meal.
Wow...ran off at the figers there.
Adrienne