Oh, and I'm sorry, I didn't address any of your questions!

1. When I first went vegan, I lived in Edmonton, Alberta. It wasn't the most vegan-friendly place, and it was frustrating to try to cook out of books that required a lot of specialty ingredients. However, you can eat GREAT using beans, grains, veggies, fruits, and pantry staples. You may have to spend a bit more time in the kitchen than you used to (especially if you're used to eating prepared foods), but once you get used to spending time cooking, I bet you will enjoy it. Look for vegan books with a focus on "whole" ingredients like beans and veggies rather than prepared ingredients like Tofutti cream cheese or mock meats. Also, your freezer is your friend! Make big batches of things like soups and chilis, and freeze them in individual serving sizes. That way, when you're busy or tired, you can just heat and eat, and you'll still be getting healthy, delicious food.

2. Just like with any other kind of diet, you have to make sure you're getting enough calories in when you're training on a vegan diet. For me, when I'm training (which I will admit to being new at), I make a point to always have lots of food available and to bring lots of food to work with me so that I can more or less eat at regular intervals throughout the day. I also add a lot of protein to my diet, which generally means I'll make up a batch or two of baked tofu, tempeh, or some kind of seitan to add to foods to up the protein content. I also will eat a LOT of chickpeas. The thing with veganism is that the foods tend to be less calorie dense than many animal-sourced foods, but really all that means is that you have to eat a bit more, volume wise. The quality of the calories and the energy you get from it is the same. It might take you a bit of an adjustment period to get into a routine that works for you, but it's totally do-able.

3. As far as supplements, the biggest thing vegans have trouble with is B12, so if you only supplement one thing, supplement that. Me, I take a multi, a DHA supplement, and a Vitamin D supplement. That may sound like a lot, but it's more of an "insurance policy" than a strict necessity. It's possible to get everything you need from a vegan diet, but that doesn't mean it's a terrible idea to take a supplement or two. I didn't supplement at all for about 5 or 6 years, and I never had any ill effects. The reason I do it now is mostly because I've gotten more nutrition conscious, and it just seems like a good idea. I don't really see it as a "con," either, and definitely not specific to veganism. Many omnivores don't get enough vitamins and minerals in their diets as well.

I hope that is helpful!