I love listening. One recommendation is to separate the statement of departure and destination airports from the others just for a quicker read. Thank you!
Inoperative trim could cause a problem if it was causing an out of trim condition that disabled the autopilot or caused continuous manual override by the pilot. (Not a pilot and could be better explained by one.)
The stabilizer trim controls the entire pitch attitude of the aircraft and reduced control forces needed for the elevator. If the stabilizer is out of trim the aircraft could become impossible to control. The manual trim works, but that is a huge workload. I’ll be diverting as well.
Just want to add on to the other comments that the airplane is going to want to go up/down based on where the stabilizer stuck. If they got it in position during the climb and then it didn't move from there, the aircraft is going to naturally keep climbing and you're going to have to push really hard to get it to level off, much less descend if you can't adjust it manually. Similarly, if it got stuck during descent, getting the plane to climb is going to be really difficult. So there are some real controllability issues with stabilizer issues. Alaska Airlines 261 is an extreme example (where the entire assembly failed causing the aircraft to get stuck in a dive), Republic Airways 4439 is one where the stabilizer worked opposite of what the pilot wanted. Mentour has videos on both.
Stabiliser has quite a large amount of leverage when compared to the elevator's effect (not enough to overide but enough to make it difficult to fly normally) . Think mcas...