jznj,
I can't answer most of your question but can tell you that, if you travel on the interstates at the recommended 60-65mph, you will average 50mph for the days travel. If you travel on the secondary roads your average will be somewhat less. This includes stops for fuel, potty breaks etc.
There is
Good Sam Camping app and
RV Parky app, both of which are available for Iphone and Android devices. I think they will help you out a lot. Also, once in Georgia, you will find a lot of campgrounds along just about any road you travel. :) I have used
CoPilot USA and found it quite useful. It is also available for Iphone and Android phones.
Barney