All valid points. Guidelines are just that, guidelines and not strict rules. I think all these questions will be clearer once we have a good idea of the strength of any evidence that may have been uncovered.
I think for Trump this is turning into a matter of strategic exiting. Best case scanrio for him is to be able to fight off any impeachment attempts and somehow win in 2020. He is going to be damaged goods for sure. If Mueller delivers something that would be arguably very substantive in court, Trump might just want to go quietly and hope that he is left alone after impeachment. If he fights a strong Mueller report, the Senate doesn’t convict after impeachment and he loses in 2020, there is a very high likelihood he’s going to get destroyed in court post presidency.
Remaining in the WH is his only option right now to continue kicking the can on all these issues.