I've seen the 02 and up Explorers (same half shaft design) lowered up to 1.6 inches with coil spring kits. But I'd be really careful with that, and I couldn't see going much over that.
for the lower, couldnt u just c-notch the frame out of the way and for lifting, couldnt u just take the shaft out and raise the truck up, and then put the shaft back in?
If you have enough money to put into the project, anything is possible. I wonder if the roll stability control system in the new Tracs would freak out if you lifted/lowered it?