Guys are lucky sometimes. My hair takes a lot of work. My husband shaves his head with a razor every morning. It takes him about three minutes and he's done.
Every 3-4 days, generally. I used to wash it daily, but it's so much healthier now that I've stopped doing that. I often spray it with a little dry shampoo on the in-between days.
You probably could, unless you use a lot of product. Even then, you might be able to just spritz it with water, rather than go for the full wash. I have my stylist cut mine so that I can wear it curly or mostly straight. Shampoo day it's curly, by day 3 it's pretty much straight. I like having the option/variety. I also switched to no sulfate shampoo. It's different, because it doesn't really lather much, but it's so much better for your hair and your health, too. I really like Avalon Organics, there are several varieties and it's not expensive.
3 times a week at the most. I wait until it’s hella greasy to wash it, even though I shower everyday. I used to wash it every day but ever since I stopped a last summer my hair has been the healthiest ever.