Tech, I don't recommend frame swaps, not because I can't do them, but the average person who is asking can't do them! Now, what you describe is NOT a "frame swap", it's a "frame clip". A front and rear frame clip, that is miles from the "frame swap" that I am on a one man crusade to end in the rodding world.
The frame clip is a way to go, I am not fond of it for a few reasons, not because they are so hard for ME or a guy like yourself who has a high amount of fabrication skills. One reason I am not fond of it is because it DOES take a tremendous amount of skill compared to a bolt on kit. I know exactly how to do it, I have done it right down to the angle finder on the control arm and your explanation is a good one but is your average rodder asking about frame swaps going to be able to grasp what you have laid out, not on your life!
This is the funny thing about most guys who ask questions like that, you or I would never ask the question, we would just DO IT because we have the skills. I don't know about this original poster,but MOST of the frame swap questions I see are from guys who are looking for the magic bullet. They are the same people who ask me at the shop "You mean you just can't pop out the dent"? They are asking about a "swap" this means unbolt and bolt in a new frame like putting a small block Chevy where a big block was, that is what they are asking.
The actual welding of the frame clip onto your old frame is just a small part of the job just as making the motor mounts are in an engine swap. It is all the dozens of other things that make it tough. And every swap is different. Knowing how to set up and measure out the frame to weld it on is going to remain pretty similar, but the rad support, the inner fenders the bumper brackets that is where the real time often gets spent, and a LOT of fabrication skills are needed.
I wouldn't think a thing about chopping the top or sectioning the body ANY car. I am a pro and have done many of them. I could chop a friggin 2007 Escalade and not think a thing of it, but I sure wouldn't tell a newbe to do it!
If someone really wants to do it you have laid out a great overview on how to pull it off successfully. As I was reading it I thought about how many guys I have worked with who repaired cars for a living who couldn't have pull it off! I know one thing, if a guy reads what you wrote and it makes sense then he is ready for the challenge.
As long as the guy who is going for it has gotten all sides and makes a good decision with the understanding of what it takes and knowing HE can do it then cool.