This is a very big thread and tried looking so apologize if this has been asked before but flying F old 777.
I have flown it plenty of times but never solo stuck in a middle seat. Do they allow to raise the partition for the entire flight or does it have to be down during takeoff/landing? I have only ever flown the middle seats with a companion. I seem to remember they do allow it to be raised.
Set a seat alert hopefully a window opens I do find the middle seats to feel more cramped and the storage compartment is definitely smaller (not sure if that is noted anywhere in this thread).
2K is often blocked. For UM use, I think. So call a day or two before the flight to be moved. Or otherwise ask at check in.