So, if he separated from his partner and established himself as a single man would you be prepared to give a relationship with him a go?
If the answer to that is yes, then that's great, go for it but, if the answer is no, or you don't know then I honestly don't see the point. If you can't see yourself in a relationship with him then considering the level of feelings involved, I think the only way to go is no contact. You need to cut all ties with him both physically and emotionally or you are going to be left 'stuck' for the rest of your days.
As for his new profession, I wonder if he could be directed to the Frothers thread and the ongoing campaign 
Zany I hope all goes well tonight, I'm sure it will 
I've just had an accident. The Christmas chocolates fell into my mouth. Closely followed by a tube of some Pringles. 