1) Am I crazy? Should I rethink the whole 2 year commitment? Can I stretch it to 3 years?
LOL! If your are crazy, then so am I ;) I think as long as you are enjoying this new lifestyle, then continue it for as long as you want.
2) How do I keep them motivated and engaged while on the road?
If your talking about school work ~> For my kids we use an online curriculum called Time4Learning, which they seem to like better the text books.
If your talking in general~> Just let them be involved. Let them give you ideas on where to go. Or when you have picked a location, learn what you can about it prior, so that the excitement builds. For example: if you are going to Florida, learn about the beaches, marine animals, etc. Then when they are there, it will make the experience that much more interesting for them ;)
3) Have any of you tried this?
I am trying it now ;)
4) Are there any "best practices" I should follow?
Relax and enjoy the experience! It's not about how much you do or how far you go, but the memories that you make together :)
5) Anything I should avoid?
If an area or campground makes you think twice, then move on or at least call the local law enforcement to make sure the area is safe.
6) What are some areas of the country we should look at in order to decide where to eventually settle down?
This is a question you have to figure out for your selves. Where one person likes the beach, another likes the mountains ;)