My experience with Behr rims goes back to the mid 90's and several Baja rides that turned into nightmares for GS riders. This trend continued into the oil heads, but at some point I believe BMW changed something? You 1200GS guys can school me here.
Since you've had (and have) other BMW's you must know that many owners who are capable do most of their own work. I learned from my BMW dealer mechanic drinking buddies back in the late 80's to never, ever bring your bike in to a dealer. (even if my buddies are working)
You really have to learn to do things your self. Back then (and I guess now as well) fellow owners would do Tech days and help each other out learning all the various foibles of the bike. Now I see guys doing DVD's and such.
This does not sit well with some BMW owners who are not willing to jump in and get greasy. Some of these guys are, rightfully so, super pissed off when they get a $800 bill for a basic service.
I wish you all the luck with your bike and getting it back on track as a good Adv. Touring tool (without the heavy Baja type pounding perhaps?)