Quito - look at the braking available after you have blown the front tyres, and the implied deceleration thereafter.
Congonhas - note the procedure changes introduced by Airbus via EASA into the FCOMs with regards to spoiler deployment or not after landing. Not seen the new knowledge requirements yet for groundschool training.
TGU - first impression (is that the right word when looking at the crumpled fuselage?) makes me think that the aircraft did not fall off the runway at particularly high speed. The spoilers may retract below a certain speed on the ground during landing roll out.
The AA touchdown "early" - please remember why the threshold is displaced and what for. The arrows are there to displace the threshold for obstacle clearance purposes associated with those hills a bit further up the approach. The use of arrows and not X and the runway's PCN number indicate that it is ok to touchdown prior to threshold, if you really want to. There may be other reasons why it is not a good idea. Oh, yes, I remember, a busy European airport had a 737 lined up and they gave another 737 landing clearance so it did over the top of the one on the runway. The investigation report's main conclusion was that displace thresholds were a good idea as they gave more vertical clearance in this situation.... another great investigation there then
I have more to add, but that is all I am allowed to say for the moment.
Discount.