1) When a jet breaks the sound barrier they can break windows if they are at low altitude, how did he not break his ear drums?
They don't break their own windows ( cockpit and cabin glass though ), do they : ?..it is about where one is relative to the air/sound pressure..but I would imagine that he was "shaken", his medical "work up" must be very interesting, as he came down in "delta", his helmet and thus neck and upper back would have been taking the buffeting..( would like a close look at the helmet and suit ), to see what padding and rigidity "extras" were included..
2) Can the fear-factor also break the sound barrier relentlessly chasing him all the way down?
Once you are committed to a jump ( have left the plane )..there is no fear :) The first jump, one is afraid..then there is elation :) and landing, and if the landing is good, there is the immediate desire to do it again..YMMV
3) Considering the standard lapse rate of 2ºC per 305 metres it must have been a tad bit chilly up there but there's no mention of him wearing battery operated wooly socks to keep his toes warm.
His helmet "fogged"..so there was a temperature difference when he opened the capsule door..but I don't suppose he was thinking about his feet..the most important thing would be not to tumble and/spin..( and if he did to be able to correct that ..which he did amazingly well :) and not to fall asleep from the cold on the way down ( even with the adrenalin rush, the sheer cold could have made him sleepy, which is why, if I followed the reports correctly, the chute was rigged to open automatically, and not by a pull on the D ring..
Would you attempt what he did if you were given the opportunity?
Were I still his age ..yes :)
your title implies you have jumped out of perfectly good planes that still had the engine running and fuel in its tanks.
Indeed..many times..but not nearly as many as Felix Baumgartner..
Btw ..long time ago here, DaveAtIFG, who has been gone now over 6 years :( asked me why some of us do that.." ( "Why does anyone jump out of perfectly good planes that still have the engine running and fuel in their tanks" ). too* ..( there was "that question", implicit in your question ;)..the answer is the same ..
There is no rush like free-fall :))
And in free fall ..one gets the closest that one can to flying..the wingsuit [en.wikipedia.org
...] brings that even closer..but even without one, small movements when falling, before deploying the chute, allow one to "track" across the sky, and indulge in acrobatics whilst falling..
Every kid dreams they can fly..Skydivers do it..:)
*In my case..a family thing , my father was ( amongst other things ) a senior military parachute instructor and a competition skydiver ( those elaborate formations with large numbers of skydivers ) ..got me into it..and flying ( where one stays in the aircraft, all the way from take off to landing ;)..and gliders and such..
** Beginners, both civilian and military make their first jumps with "static line"..their chute's opening system is attached to whatever they are jumping from, and is thus opened for them in case they "freeze" with fear..military paratroopers are on "static lines" ..when they are "deployed" ..their parachutes re not the same as those used in Skydiving..