In regards to MANPADS, I haven't read the wikileaks documents but as I understand it, the threat comes from Stinger missiles (FIM-92's) which we're originally given to the Mujahideen during the Russian occupation, these have a range of about 16'000 feet so shouldn't be a realistic threat to overflights, even if they are firing them from the high-ground.
Stingers aren't the only MANPADS in Afghanistan, but my info is a couple of years old
Another point that was told to me was that the Stingers batteries will probably not be reliable after all these years.
Yep, the quality of upkeep of those Muj Missiles is an unknown.