He asked for an expedite on the basis of his medical issues and that you being interviewed earlier as opposed to waiting your turn would help.
They need medical evidence to support that request.
The most common route I have seen is find a USC SO.
If you are looking to go via work better to focus on a subject where work sponsorship is more common.
Canadian and K1 makes zero sense to me, maybe there is one in a million scenario where it does?
I have come across people who have been able to get back in, and those who have not. You definitely stand a chance.
Nothing a Lawyer can really do with a F1.
All I can think of is if you basically have a perfectly solid F case and this can be put down to youthful foibles they will let it pass.
It is not normal for subsequent applications to be approved but it certainly seems to happen.