Yes you can have the ductwork cleaned. And as I said from the start you should have a pro come look at your situation and they should be able to get the coil cleaned as well as the blower and recommend the best strategy for getting the ductwork taken care of.
As for the flame noise your hearing, you should have a pro come in and check your gas pressures and make sure your system is not over firing. But as far as something you can do, no there isn't. Everything from here on in requires a pro to come and examine the system, make sure it's operating properly and offer suggestions on how to clean it up.