#2
it's very possible that the trip caused this problem, changes in weather and the flight and a whole bunch of stuff could have affected it, of course the guy could have been incompetent, but chances are he wasn't because it's pretty easy to adjust the action, if you aren't keeping it properly humidified you've gotta get that sorted out, before you get a new saddle or anything try adjusting the truss rod, don't force it, be gentle, but with a few turns of the rod the neck might not settle for a few days, just take it easy, chill, have faith, fill your heart with love
#3
it's very possible that humidity is - and was - the problem. that can cause the action to change quite a bit. do you use a hygrometer that's been tested and calibrated?
Quote by Skeet UK
I just looked in my Oxford English Dictionary and under "Acoustic Guitar", there was your Avatar and an email address!
#5
depends on how dry it is, it might take a few weeks or more (or less) to re humidify if that is the problem, you should also get to know your truss rod a bit, experiment with a few small turns, don't over do it or force it, and make sure you have the right tool to turn it