All three of those items are easily identified in a PPI, including the quality of the trans fluid. Known issues with known causes and known solutions.
In particular with a PPI of the trans, sure, I guess you could warm the engine to spec, quickly pull the transmission overflow plug, and quickly replace it, to get a sample of the fluid. Although, this happening in a PPI is surprising to me... good luck convincing a private seller to let you do this. (Unless there is a better way to sample the fluid on a sealed transmission?)
Regardless, all your doing at that point is "eyeballing" the fluid that it's not cooked black. Hardly a scientific analysis of the fluid's condition or wear metals detected that only a company like Blackstone could provide.
And with the other items, given the context of long term, out of warranty reliability... just because the problem isn't discovered at the time of sale, doesn't mean it won't become a problem in the future. As you say, these issues are well known to occur.