Mites don't cause swarming or starvation. If he is buying mite bombs he needs to find another supplier.
Mites DO cause losses.
First of all, swarming doesn't cause wax moths that the OP described. Secondly, the OP mentions catching one swarm. Did the OP see the others actually swarm or just assume?
I have seen very similar results from beginners who did not treat. Rusty has a very nice write-up ->
http://honeybeesuite.com/did-they-abscond-or-die-from-varroa/Like Rusty, I don't buy into the absconding. For all the folks that have had this issues I have not heard of one actually seeing or finding the swarm, nor have I had any reports of late fall swarms. "Absconding" was unheard of around here until a few years ago when this phenomena started to happen.
It seems to happen to those with no, or hokey, treatment plans.
Swarming does not cause winter loss, and from looking at his frames with honey and the fact that he said he fed them I doubt it was starvation. Seems to me that he has bought from 3 different well know supplies so the issue is more than the source of his bees.
I would be hard pressed not to recommend varroa treatment for a beginner.
OP can do what he chooses, but unless he address varroa he is just chasing symptoms.