What a bummer. Broken parts bouncing around inside your engine! You can't ride anywhere with confidence those parts aren't going to cause the engine to lock up at the worst possible time and cause even more damage or a wreck.
I feel very fortunate to have a 2010 with 93k miles, no serious issues, 2 cross country trips, never left me stranded, and my valves haven't needed adjustment. I have checked my valves several times and pulling the plugs is not necessary because their is no compression when the engine RPM is less than 600. If you can lift the rear wheel off the ground, their is a relatively easy way to check if your de-compressors are working.
Pull the right side cover and water reservoir so you can access the front belt pulley. With the bike in gear you should be able to use a wrench on one of the pulley bolts and turn the engine over. Make sure you pull it in the forward direction only. I don't remember the torque on those bolts but the engine should turn over before the bolt moves because their is no compression.