Thrawn,
Why do you not trust airline pilots to handle sidearms in a responsible manner? Most of them are ex-military, trained to handle stress situations and with fairly extensive experience in handling weapons.
The use of professional peace officers as airline security would not be adequate to counter the threat of a terrorist team. The terrorists responsible for the acts of 9/11 had gone through extensive training, part of which, undoubtedly, had to do with spotting undercover security officers. If future terrorists are able to "make" these officers and overcome them, what is to prevent them from repeating those acts? The newly "reinforced doors?" Those can be blown or cut through.
The last line of defense for the passengers and crew, through sheer elimination, has to be the cockpit crew.
Had the pilots been armed with something as innocuous as a .22 pistol, the tragic events of 9/11 could have been avoided.
Oh...and decompression would not be a problem, even with a large caliber pistol.
Regards, Shuckins