I talked to my vet about it last month and he recommended we test Flame's calcium levels to rule out tremors caused by calcium deficiency. Since I was taking the two chams in today, I brought Flame along for the ride.
While he was at the vet, I was able to take a video of his head tremors. This is moderate for him-- so sometimes it's less noticeable and sometimes it's worse.
The calcium levels are right on track and so the vet tested the phosphorus levels (which can indicate kidney disease which also causes tremors). The phosphorus levels were right on track too. That leaves us with our original guess-- that he has a neurological issue due to inbreeding.
It is VERY common for "Fancy" bearded dragons to end up with genetic problems because of too much inbreeding. When you want a specific trait (like a leatherback or translucence or red coloring), you must use a specific set of genes to get it. There's not as much variation in the gene pool for these traits. With "Normal" colors, there are hundreds of thousands of beardies to chose from and there are far fewer problems that manifest. Silkies (what you get sometimes when you breed two leatherbacks) are, in my opinion, the most genetically messed up beardies. They have the most problems and difficulties.
So Flame is not fixable and, based on my previous experience with translucents with tremors, is not likely to have a long life. He will be loved and cared for while he is here. I won't adopt him out because of how valuable he would be as a breeder. It would be absolutely WRONG to breed him since he's already genetically messed up. To make sure that never happens to him, he's staying with me. Plus, I finally got him to let me pet his head without him biting me. I can't pet anywhere else, but I can give him loves on his head.
Checklist for Head Tremors--
1- rule out Metabolic Bone Disease caused by calcium deficiency (blood test)
2- rule out phosphorous deficiency caused by kidney disease (blood test)
3- conduct an overall blood panel test to make sure there are not other underlying issues
4- look at genetics
Benign head tremors are really only a problem when they are unable to control their heads enough to eat. If this happens, the beardie will have to be assisted with its food (like crickets on tongs) or tube fed.
