Addressing the desert issue - I found it!
http://www.fallout3nexus.com/downloads/file.php?id=10815
This mod is awesome here are some pictures!
http://www.fallout3nexus.com/downloads/images/10815-1-1268511187.jpg
http://www.fallout3nexus.com/downloads/images/10815-1-1267651222.jpg...
Here's what i think we could do.
Same old vault escape crap but instead of being forced into megaton/3dog/ main quest.
Just get a quest that has no markers or anything that says something like "search the wasteland for signs of dad" and u would have to go to cities/town/any people you can...