All your points are reasonable, but I don't think the masterplan requires anyone but him. He's gone mask off as far as being ok with or even promoting hate speech of various flavors, and twitter was increasingly hostile to those sorts of folks until he took over. Unbanning Trump was damn near the first thing he did.
He strikes me absolutely as childish enough and rich enough that (incorporating also your "he doesn't really want it" point) buying it, doing everything he can to run it into the ground, then folding or divesting it (who would want it now?) when he thinks he's destroyed it as deeply as he can.