Well, I don't know how rookie it is to lock the center diff to be able to get home, people do it quite frequently it seems, and I would think a rookie wouldn't even think about the option. But, since your entire front axle assembly (from the hubs to the pinion) has been spinning as you drive down the road sans front driveshaft, and you had no vibration; I think I'd first consider that there is a balance issue with the new driveshaft, or an issue with the driveshaft u-joints. Either a bad u-joint, or they just don't like the driveline angle (how much lift do you have on it, and is the front Castor corrected in any way?).
I think I’d investigate this possibility before tearing my hair out too much trying to troubleshoot the front axle or transfer case (though if the center diff was unlocked when the front shaft let go, it is possible the center differential in the t-case could have been damaged, but I’d doubt you’d have the center diff unlocked in the conditions you described).
Disclaimer: However, I am not a certified mechanic, and I have never stayed in a Holiday Inn Express, so I suppose you should take my advice with a grain of salt.
P.S. -- 3.11 axle gears? I think all the NAS Defenders had 3.54's stock
It would seem odd that someone would go taller..