HM:
Sorry, can't answer many of your questions.
(I only work here..)
As for lost bags;
Well, don't know that it is a big problem here in the US.
Speaking strictly from personal experience I have "lost" bags 3 times in my life.
(Millions of miles dead-heading/commuting/vacation, etc.)
Once on BA, connecting at Heathrow, another time on Iberia, connecting in Barcelona and the third time on Midway airlines in Miami.
The last ten years seems to have been good for pax and their bags.
(Computerized readers and other magic stuff employed at hubs)
If other travelers however have had bad experiences here in the US, I may be wrong.(For the first time of course
)