I just love it when folks suggest you look to your UC to get involved. Perhaps ours is in the minority, but we have no UC for our Troop - never have. Other folks will suggest talking with your COR - ours could care less about what goes on in our troop. Chartered Organization - ditto non involvement. Committee Chair - we've had 3 in the past year and a half.
Sure, the chartered organization signs a contract each year saying they will provide and approve leadership for the troop. How many actually do that? Hopefully, my experience (14 years - 2 cub packs and 1 troop) is the only one in that the CO is not involved AT ALL in providing leadership.
Sounds like doom and gloom doesn't it? Well, for several years, our troop was very much in the same position as yours. Very close and cliquish adult leaders as SM, ASMs and Committee. Cancelled meetings because of other obligations. Cancelled outings for similar reasons. Of course, all their boys were advacing, almost in lock-step. Amazing how that happed since the troop took no more than 5 campouts a year including a week of summer camp. Add to that no recruitment and eventually everyone just got tired.
The result, a completely adult run troop and, by the time I was tapped to SM, only a handful of boys - two under 1st class, the rest at Life and biding their time.
From what you've posted, even as CC it seems you really wouldn't have any way to improve your situation if you are fighting the battle on your own without backup from the chartered organization, rep., or unit commish. And, just from personal experience, be prepared to back up with action any complaints you may bring to the SM. If he steps down, you may just have to be prepared to take his place.
That's how I became SM!
Good luck to you and your son.