Re Parachutes: It has been done. At least twice.
A passenger jet HAS been modded to allow exit with parachutes. It was Concorde, no less! You can even see the mod for yourself: get thee to the Fleet Air Arm Museum at RNAS Yeovilton, go to Hall 4, and look for Concorde 002 (you can't miss it, it's the huge totally awesome one). Go inside (yes! you can go inside!!!) and look for the emergency escape hatch in the floor. From memory the hatch is on the right side near the rear of the cabin, but it's been a while... anyway, the hatch is in there somewhere. The hatch also features a handy metal plate which slides down to disrupt the airflow so you can exit reasonably un-mangled.
And, of course, there was Dan Cooper.