1 & 8 - luck of the draw. Broken seats happen and bus gates/remote stands are a thing. Try not to lose sleep over these.
2 - not sure, I was on a 777 to DXB in late 2021 and pretty sure it was old club world from memory. A little dated but perfectly functional.
3 - I'll confess I thought even the oldest 777's had USB in J but unsure if that is advertised/'guaranteed'. I tend to only use it on longer flights and generally carry adapters anyway so might not have paid too much attention.
7 - I've never had a call bell ignored in J, if the cabin was truly 'abandoned' that's bad. Was this one of the planes with two J galleys, and a chance you were going to one they weren't using (or only using during main services)? Was call bell ignored?

I get this is a forum vent but 4, 5 and 6 (other than 'no gold recognition') feel worthy of contacting BA, alongside IFE not working if it wasn't (beyond "they rebooted it a couple of times"). i.e. making them aware of poor service/missed service components. If you do I'd avoid complaining that seat moves can happen when seats have faults, aircraft are old and you'd rather someone else had to fly them while your route got something shinier, and that you had to go on a bus detracts from the things they can realistically do something about.