I'm not sure where to start picking the holes. I guess from the top:
RTLS, return to launch site, requires separation from the main tank and SRBs. Despite NASA's design changes most of us old rocket scientists think that will detonate the tank. Separating from the SRBs requires a hard pitch down to avoid the SRB plumes, which in real life the shuttle does not have enough aerodynamic command to achieve.
Considering that there are NO abort modes that happen before SRB separation, you're talking shit there. An RTLS, the earliest abort you can do after the SRBs have been ignited, can only be called after 123 seconds (When SRB separation happens) and before 150s after launch, or a call window of only 27 seconds.
Also, the shuttle does not have enough cross-range capability to achieve a Transatlantic landing at any facility capable of handling it. An attempt at TAL will result in a water landing with loss of vehicle and crew. TAL is bogus and NASA knows it.
Uhh, what? Considering the earliest time you can call an TAL the shuttle is 400,000 ft up and 400 NM away from Florida, a ballistic trajectory gives the shuttle more than enough cross-range capability to land at the requested location (for ISS launches that's basically always ZZA).
Abort Once Around suffers from Earth rotation and the lack of sufficient cross-range capability. All viable landing sites are just not available on a once-around.
Again, what? An AOA means the shuttle enters a low orbit that is not stable with the express means of doing two OMS burns giving it the re-entry profile of a normal end of mission re-entry. An AOA can only be called after a TAL can't be done but before an ATO is called. This is a window of just a few seconds, so the chance of needing to do an AOA is slim even if things are going wrong. Since an AOA is still technically an orbit, the cross-range capabilities of the shuttle are that of anything orbiting the earth; anything is reachable within 90 minutes.
Now, about the Crew Escape System (CES), which are "tractor" rockets that pull the crewmen out one at a time. The shuttle reaches 25,000 feet in under a minute. At 35,000 feet its breaking the speed of sound. It seems the only way the CES will work is if you shut the main engines down.
This just highlights how clueless you are about shuttle abort modes and procedures. The CES would only be used if you could not land the orbiter, but after you had either pulled an RTLS, TAL or AOA. You could never exit the shuttle during launch, so I'm not even sure what you're thinking about shutting the main engines down. An RTLS, TAL and AOA have a flight profile that allows the CES to be used if required.
Back in the the 1960's, the F-111's entire crew compartment ejected.
The F-111 seated two. Next to each other. The shuttle seats six or seven on a normal mission, and only four are anywhere near each other. The other seats are in the mid-deck, with a substantial amount of shuttle around them. An ejector system like the F-111 would be impractical due to weight, be unusable at launch and only usable after a successful re-entry. Thus of the two shuttle accidents that have happened, such a system couldn't have been used. For either
NeoThermic
P.S. Mexico City isn't a landing site and never has been.