L1ftmech,
no cryptic answers here buddy
to answer your question about any further damage that may occur from a mal adjusted pps?
other than it not wanting to run correctly? none that i know of.
The pps and the tbs were not aligned so it didnt know what to do... plain and simple :o)

installing a pps is a fairly simple thing if done by a professional with the right tools. I've seen too many techs try to play it by ear or eyeball it and thats just not possible and get it "right".
I'll bet you they did this and got it wrong and couldnt figure it out. Being that all you did was relearn the system and it returned to normal pretty much tells the story doesnt it?

Send the truck back, send them the bill and smile and say "have a nice day" ;o)

Job well done.