Since your family is a fan of picking apart anything new in your life, it sounds like this year's holiday events will be the same as ever

One thing that I do and highly recommend for
any occasion where you're not hosting the meal is to insist that you cook with the host. Here's what I say: "Thanks for the invite! As you probably know, I'm vegan, but I don't want you going out of your way. I would like to know what you plan on making for the menu, and then I'll come by early and help you cook. Any dishes that can easily be converted into a vegan dish I'll make vegan. This way, you get help and I can ensure there's food I can eat." A typical American Thanksgiving (I don't know if you do anything different being Italian...I know my family, which isn't from the States, celebrates with some "traditional" food and then
our traditional food) includes things like mashed potatoes and gravy, stuffing/dressing, green bean casserole, corn on the cob and cranberry jam/jelly. That's awesome, since all of those can
easily be made vegan...or vegetarian

When I visited my mother's house for Thanksgiving two years ago, I made the mashed potatoes using roasted garlic, soy milk and vegan butter. I made the green bean casserole from scratch by making a mixed mushroom cream soup using garlic, various mushrooms, soy milk and corn starch (to thicken). Then I poured this over fresh green beans in a casserole dish and topped with everyone's favorite crispy onion straws (which are vegan anyway), then baked as usual. We had never had a green bean casserole made from scratch and everyone really enjoyed it. Corn on the cob is a no-brainer: just make sure no one pre-butters all of them. If your family stuffs the bird on Squash Day, ask to make the stuffing first, then remove a portion for yourself and have them stuff the rest into the poor turkey carcass. Just make the stuffing using a mushroom or vegetable broth instead of chicken/turkey/beef/oyster broth and you're set.
This way, they get help in the kitchen and also get to see that your vegetarian food isn't "weird," it's all the stuff they already enjoy.

The fact that you enjoy cooking will really help you with this!
Mock shrimp is usually found in an Asian market (in fact, I've only ever found it there) and it was soy-free. Actually, it was made with regular, all natural ingredients. Writing that made me wonder if there are recipes for it and asking Ms. Google returned this at the top:
http://feedingmaybelle.blogspot.com/...hrimp-dim.html This is a mock shrimp made by cooking eggplant in broth using seaweed and other ingredients. That seems pretty easy to me!
If you want to use wheat gluten (seitan), I found this recipe here:
http://www.indiadivine.org/audarya/v...ck-shrimp.htmlUnShrimp
1 recipe basic gluten
1 gallon water
1/2 cup MSG
1/4 cup sea salt
1 bag Zatarain's crab boil
1 T corn oil
-Cook gluten, slice 1/4 inch thick and then cut into 1 x 2 inch pieces (or into shrimplike shapes). Combine rest of ingredients and simmer for 5 minutes. Boil the gluten in the broth for 30 minutes. Then let it soak overnight in the broth, keeping the crab boil bag in the broth as well. Drain before using.
-It mentions that if you want less broth, open the bag of crab boil, measure out a proportionate amount, tie in cheesecloth and use that.
I don't know if I'd use MSG but that's up to you.