UPDATE: Well, Yamaha has determined that this problem was a result of a manufacturing defect and is honoring warranty relief for a replacement tank. My only out of pocket expense will be an hour of labor to install the tank on the bike (due to liability reasons). Hopefully this defect was just something on my bike, and no one else will succumb to what I've experienced. I'm relieved (and happy) that Yamaha has stood behind their product - thanks Yamaha!
Good result, although I don't see why you should be charged for the labour. It wasn't your fault it was defective. If Yamaha insist on the dealer fitting it, IMHO they should pay.
Depends on whether you want to fight it.
The easy way is to accept things as they are and just ride.