They previously accepted him. He's worked closely with Loomer and Milo in the past. They will do so again provided he's willing to be used, and there's no reason to think he's not.

Theoretically possible, but it would require the sea-change in pol attitudes towards Israel that you have already predicted. Right now, it's a third rail and the norm is to slobber all over the boot.

In the current context though, I don't see Fuentes gaining anything from switching sides.

You're talking about people who have worked with Syria's new Al Qaeda leader. Fuentes isn't even close to being too much for them.

But Al Qaeda in Syria has always been their instrument. Did you see Petraeus slobber over Jolani? For them, it's obviously not a matter of how far you are beyond the pale morally. Any foreign faction is OK (see: Nazis after WW2, Japanese war criminals, Al Qaeda, Azov), domestic factions can be a political threat so they are not.