Heck no you are not crazy. I think that is just great! I homeschooled our daughter for one year (for fun and there was a local homeschool group she could socialize with).
Go year by year and see how it goes. Get the books from your school (for free) to see what the school would be teaching to give you an idea...doesn't mean you have to go there but for things like math it will be important.
Motivated? The world is their school yard...so much to see, so much to learn, not confined to the classroom, every day will give them many things to learn by doing...way better than any classroom (that I ever attended). National Parks, new evironments (desert, etc) to experience, new flora, new fauna....
JUST DO IT!