You are absolutely spot on. They initially tested the ejection sequence with the Pilot going first. Almost all of the dummies in the rear sustained very bad burns and if they were actual humans back there they would all end up dying because of the 3rd degree burns that they would of sustained. This, I believe, lasted no more than 5-7 more tries and variations before it was completely dropped from the plan.
Your second statement is also spot on. B-52's are exactly like that. They have chairs that will leave through the bottom of the aircraft; turn them upright and gain a lot of altitude before he/she are forced to leave the seat. I believe from what I have been reading about them for years that it will take them upwards at a slight angle so they do hit the bottom of the airplane during the ejection sequence (EJS). The bottom Navigator, Weapons Officer, and the Flight engineer are all located in the bottom of the the airplane in a B-52. Either way you look at that EJS, you are going to be shot up on a rocket seat to an approximate altitude of 800ft before the recovery sequence starts. Some airplanes in our USAF and Navy have the ability to start the sequence initiated by either Pilot. That is to say that for example, I am in the back seat as a WISO/GIB in an F-4 and the pilot gets hit from a 12.5 or a 14.5mm round thru the side of the canopy and we are starting to go down in flames from other hits, he maybe OK and just knocked out from the large fragments that hit him in the side of his helmet, or he may be in fact dead, Either way, I can start the ejection process from the rear. I will have about a half a second lead when I punch out before he goes. Both himself and I will still land on the ground OK and he would wake up from his knock-out not remembering anything other than flying the airplane. Same goes for the co-pilot. If he is injured badly from a hit and we get more hits from AAA and we are going down, he can start the EJS himself. I will still go first and he will go a half a second later.
With the advent of ejecting from an airplane say, such as one of the Century Fighters, they all can go over Mach 1 under ideal conditions or for just hauling arse away from the Russian built Fighters/AAA, that caused a lot of very different problems when ejecting over the Mach number. A lot of times when airmen eject in Mach they will have their oxygen mask ripped away including everything attached to his flight suit and a great percentage of broken bones and/or serious injuries such as in the head and neck. You will sometimes see that in some airplanes that can go over Mach two separate ways to eject. You will probably find a "D" handle between each seat and a checkered Yellow and Black rope type of a handle right above them. NOTE: Anything to do with the EJS or for emergencies in an airplane will always be of a Yellow and Black color scheme and possibly the same shape and size. This is so, because if the pilot(s) has to eject at Mach, he will probably be doing it from a near hit from a near mis from an exploding "Continuous Rod" type of warhead on a missile such as from the SA-2 that was used in incredible numbers during the Vietnam War. Hey, when you can get them for free from the Russians why not throw a few up to knock down one airplane or maybe hit nothing at all thanks to the Shrike and Standard Arm missiles and the Wild Weasels back then. Sometimes they just do not have to miss you with that missile, they just have to get close. Anyhow, you will not only loose those things mentioned above but you will get somewhat knocked out (these injuries are from say the F-105 Thunderchiefs used in the Vietnam War), your eyes will probably be bruised, just like you got into a prize fight, and your arms will flail up in every way possible and sometimes not, but this is the way you break your arms. Oh, and I forgot your knees hitting the cockpit on the way out too.
These two handles can cover the hole gamut of supersonic speeds and attitudes of the airplane such as high "GS's" in a fast rate flat spin. In this case you just let your hands climb up from your stomach to the "Vail" and pull that over your face which will initiate the EJS. If that is not possible then you can slide your arms downward and grab the "D" handle between you legs and pull it up towards you groin. Let's face it, you are still going to get hurt either way, but at least you will live. That is in some pain. You will have Aspirin in your survival kit/airman's kit in your vest. It is called, no kidding, a "Pain Killer"!
If you ever have the time to study some ejection seats and how they worked (By the way, I have a book written about ejections and those who did have to initiate the EJS.) try and find the EJS for a B-58 Hustler. It is like no other seat. A very interesting read.
Here is another one of my loooooong posts on an excellent question from EOD. I hope I answered your questions and doubts.
