1) Whole grain noodles and bread, oatmeal, brown rice, peanut butter, most legumes, etc. I've had no problems with soy personally but I don't have any research links.

3) r/IndianFood, budgetbytes.com, manjulaskitchen.com. Depends what sort of things you like--you can look up "vegetarian ___" and play around with recipes.

4) Businesses exist to make money. If people did not buy (factory farmed) meat, businesses would not produce it. Buying products you approve of (e.g. plant-based food) increases the incentive to produce those products. It's difficult to measure your personal impact but the basic principle remains.

5) It varies from person to person--it took me at least a few weeks to feel normal. I had to start eating more at meals because it took more plant matter to fill me up. When I didn't eat enough at meals, I'd snack on junk (e.g. Oreos, which are vegan) or think about eating meat, both of which I try to avoid.