I hope
@Cap someone can help you with the advice (I'm transporting my Vado in a station-wagon...).
Regarding the derailleur pulley: My brother was wrong. It is very hard to do any damage to the excellent Deore XT pulley. The symptom was the tension pulley seemed to be stuck (could not rotate freely). Actually, it was covered with thick and hard layer of debris that looked as if the outer surface of the cog got damaged. In fact, good deep cleaning revealed the perfect shape of the part, and no issues with rotating it anymore.
What I am worried though is the erratically behaving chain (with the problematic link removed after it broke, and replaced with a Quick Link) that is still skipping above 6th gear even if the cassette and chainring appear to be in good shape. I feel the chain got somewhat bent making some link stuck. I would replace the chain -- ordered one indeed -- but it is hard to imagine how difficult it is to get a 11-speed, 126 link new chain nowadays! (The chain was replaced only 7 weeks ago and the stretch is minimal - what gets?)
And them brakes! It was not so long ago I had to replace brake pads in the front brake, now I need to do the same to the rear brake...