Well I'm a vegetarian so I'm not sure how much help I can be on the vegan front. In terms of the vegetarians, I think you will have no problem at all. There is something vegetarian on almost every menu--of course, usually there's only one thing so there's not a lot of choice.
If I were you I would try to plan table service meals around restaurants that appear to have something vegan (or easily made vegan) on the menus already. (I know that's hard since you don't have a list of ingredients though.) And continue to try to talk to the restaurants about the ingredients in those entrees.
Some things I thought of:
-- Boma: I'm almost positive there are numerous vegan items on the buffet. Plus, I've seen many photos of people with one of the chefs. He is apparently very willing to come out and talk to people and make special entrees for folks (I see a lot of fried oreos in pics too--boy I should have asked for those!)
-- Signature restaurants: These restaurants don't seem to have many vegan options, but I do think since they are a little more upscale the chefs are probably more willing to do special entrees than at some of the more casual restaurants. We went to Flying Fish a few weeks ago and there was nothing vegetarian on the menu. I asked about a vegetarian entree and the chef came over and offered to either make me a pasta dish or make me a tasting dish. I went for the tasting dish and felt very special! (The chef also made a point of getting clear on what things I do and do not eat and asked if I had any other food preferences.) California Grill usually has a few different vegetarian options (including something called "the vegetarian unplugged"--a tasting plate of other vegetarian sides/appetizers on the menu).
-- Ohana: I'm guessing the wontons and dips, mixed greens, and veggies are vegan. They also made me an entree w/out meat that was a stir-fry with fried tofu in miso broth; this might be vegan except for the noodles which maybe they could replace with rice? Unfortunately there is only one dessert here--a bread pudding--certainly not vegan.
-- Kona Cafe: I had a lo mein type dish here w/out the chicken. The menu says it was made in a "vegetarian stir-fry sauce"--I suspect the sauce is probably vegan. Again maybe the noodles could be replaced. The Kona salad (greens, gorgonzola, fruit, nuts) would still be good without the cheese. Not sure about desserts here.
-- Spoodles: This might be a good option since it's Mediterranean based. They have a hummus appetizer and a mediterranean dips appetizer (olives, nuts, 2 kinds of hummus, tzaki, and feta cheese). Also when I asked about other vegetarian entree options they were pretty accomodating.
-- Le Cellier: There is only one vegetarian entree on the menu and I think it rotates. I had it a few weeks ago and it was delicious. It was black bean/corn/onion filled red peppers topped with cheese and a peanut sauce noodle lo mein. I suspect it could be adapted to be vegan without too much trouble.
Good luck--hope you have a great trip!