Girls will read books about boys or girls, but boys will only read books about boys:
False. The gender of the protagonist in children's or young adult's literature does not matter. For example, in the 90's, Goosebumps was really popular. About half of them had first-person female protagonists. This more closely ties into subject matter. Something like The Princess Diaries--written for and by females will largely be enjoyed by an exclusively female audience. Something like The Golden Compass/The Northern Lights, which has a female protagonist but has subject matter like adventure, is very accessible to both genders. If you care about having an egalitarian audience, and you know how to write well—whether or not you use a female protagonist—you will most likely succeed.
You need to revise your novel/work like 10 or 20 times until it's perfect
Honestly if you're efficient, and you pay really close attention, you only need to do it like once. (Unless