I travel a lot and my mbp is either sleeping or shut down, and I've never experience anything from the above. I've flown through JFK, multiple airports in Europe, and Cairo airport in Egypt. I always place my stuff in the plastic bins, and never ran into any issues.
To hell with airport security, don't use your MacBooks in the airplane. Airplanes fly higher than the recommended altitude on the spec page.
Now, for that bridge in Brooklyn.
Well lets thank Boeing and Airbus for pressurising the aircraft cabin so it's more like 8000ft in terms of pressure than 40000ft....
Those recommended altitude refers to the 'real' altitude NOT the altitude plane is flying..
Another issue to be aware of is that if you have sensitive data on your computer, even if encrypted, just being in sleep mode is not enough to prevent someone from retrieving the encryption key from memory.
Say you are leaving a country that is known for industrial espinoge. You have all you companies 'secrets' on your MBP, with full encryption on the HD, and before leaving for the airport you just close the lid and it goes to sleep. When going through security some guard grabs you and your laptop and takes you to a separate room for a couple minutes and says they have to examine your laptop and they leave the room. You have two options at this point: 1) Sit there and comply or 2) throw a fit and end up in some third world prison. Now if your computer is in sleep mode their are ways to quickly pull the encryption key vice if it was powered off (for at least one hour before hitting security).
Sounds a bit extreme, but it can happen, and stuff like this does happen around the world.
Happy Flying!
Here's an interesting presentation on the weaknesses of FileValult. Despite the website name, I don't think it is actually from the NSA (which would be a .gov website). It looks like the domain name is owned by an individual.
http://crypto.nsa.org/vilefault/23C3-VileFault.pdf
Looks like NSA didn't like the use of NSA in the domain name. The site no longer loads.