wow, a lot of doom and gloom!
On the other side - I got nothin'.
For me looking at that, the expectation would have to be - get the body off the frame, be prepared to replace or fix the frame right (measure weld measure straighten cut weld again measure again, repeat), and be prepared to go through the body panel by panel. And you end up with a gem but you earn it.
Not trying to scare you, just trying to answer the question you posed. Never "too much" if you are eyes wide open.
I just went through the above scenario on a 69 gto - but learned a ton about frames and welding and body work which was rewarding.