I see you've asked for comments, but I'm not entirely certain about what, so I'll make a couple of observations and draw from my own experience with these things.
Yes, it is a small world. I've had those uncanny encounters many times. I'd just assure your son that adults tend to navigate these issues and he shouldn't concern himself with it or let it affect his relationship with his friend.
I noted with my X that any time I told him what I wanted, it was almost a guarantee I would not get it. He had a need to hurt me and take from me the things I valued most. I assume this is his own issue and I try not to take it personally. What I will tell you, is that I left without something I thought I needed, only to find out what an albatross it would have been for me. I had to let go of many of my own perceived needs to get it done, be divorced, and finally have some peace. While I thought for a very long time he was the one who couldn't finalize it and couldn't let go, maybe it was me. When I did let go of care about what I kept and did not keep, it ended.
I want to be honest with you, and this is largely based on my own experience. I have a hard time picturing how you will ever keep that house. It sounds like the place where all of your assets are tied up. You guys can't work together to come up with a plan to keep it. I don't get the idea from you that your jurisdiction is one where you are going to be able to keep it if it comes down to the judge making the decision (and that seems to be where yours is going). I think the judge sent you both a strong warning in denying both of your motions. I wonder how you would ever get a loan to try to buy him out based on what you have said about your finances. From here, it sounds like your determination to keep it is the reason this has not been done.
At the end of the day it does not matter who sells your house or what they list it for. As long as they put it on MLS and the pictures are good (something I would try to keep some agency over, like approval of the listing), the market will tell you what the house is worth and what a buyer is willing to pay for it. If you price it too low, you will get many offers above the way the market has been. If you price it too high, the market will tell you and you will get none or they will make low offers. If your goal is not to sell and he prices too high, then it won't sell and you have nothing to fear; the experience will teach him about the value of the home more than any appraisal ever could. Perhaps then he would be willing to entertain one of your deals.
If you told him that he can choose whomever he wants to list it on two conditions, would he go for it? Condition 1--you get approval of the listing/pictures. Condition 2--you get to match the offer price (which I think would require you to have funding in place) by providing proof of financing within x days or it goes to the buyer. If you can't do that, again, I'm not sure how the court could make a ruling where you get to keep the house.
Everyone has to reach their own place on these things, but I don't think coming up with unkind names helps you, it causes you to vilify these folks in a way that keeps you entrenched. Very likely the realtor just wants to make a sale in a very competitive market where you are. That does not make him a bad person. Even if he has unrealistic ideas on the value of the house, as I've explained, that doesn't really present a problem for you if your goal is not to sell. Until you test the market, your perceptions and his will remain just that; hypothetical battles over something that can be resolved with an action.
I'm not expecting you to agree with me, and I'm sure you will have a million excuses for why it won't work (I too had many excuses for a very long time), but I say these things to you with care about what you have endured and a desire to see you using your many talents on something more productive than banging your head against a wall for several more years. I'm not sure what good you see in making offer after offer. At this point, they are likely all just noise. Just to change it up, if you aren't willing to do what I've suggested, how about going very, very quiet. No more offers, no more motions. Give him some time and space to see how he might step into the void.
