if all it will do is backfire sounds like it might have blown the carbs off the carb boots or had the flywheel move on the end of the crank(sheared keyway,loose)..check both
Haven't heard that one yet, hopefully it isn't a sign of things to come. Sounds like an ignition problem though. Sometimes she lets out an impressive pow if you don't let it idle down a minute after pinning it.
Sounds like a teather/DESS issue ... my '07 did the same thing so I swapped out with my spare and it fired right up. Dealer replaced the faulty plug with a new one. I'll never ride without a spare again