I'm looking into booking a flight with rewards travel and I'm just a little confused about how to figure out the official # of spots left on an AA flight.

The things confusing me:

1) just to make sure I understand this correctly, when you see the little orange squares on the seat diagram that means that those seats haven't been unassigned yet, but does not mean that there are that many spots left on the flight?

2) when you use a search engine like Bing Travel, it sometimes will say "5 seats left" or whatever on your search results, is that the "official" # directly reported by AA?


3) When you use the "hold" feature on the AA website, that is officially reserving you a seat for the time being (until the hold deadline) right? If I waited right before the hold deadline to finally purchase the flight I would be guaranteed to be able to do that and get a spot, right?

Sorry for the long post, and thank you for your help.