The sound that I hear from both sides of the engine sounds like my bike. My ears may not be the greatest, but I don't hear anything that scares me. Since Doc mentioned it, maybe I hear a faint rattling???? I don't know. I have about 3000 miles on a valve adjustment and very few miles on a new rotor. The "whirring" sounds are normal. If that sound is real, maybe a little bit of cam chain slop like Doc mentions.
I don't hear anything that scares me, but if the valves have never been adjusted and it bothers you, it may be worth the peace of mind to go ahead and get the valves inspected / adjusted. Doc is correct, when valves go out of spec on these, they will almost always get tighter, and should not be loose and noisy.
Part of the valve adjustment procedure is to replace the valve chain guides and reset / check the valve chain tensioner. The scheduled valve inspection is at about 30K miles, so it's not a bad idea. Mine went 45K miles before it's first adjustment, and it seems happy.
If you are not comfortable doing the work yourself, be sure you take it to a mechanic that you know you can trust. Interview the mechanic that will do the work. If the mechanic claims to be an expert that doesn't need no stinking service manual, or knows more about the bike than Yamaha, find another mechanic. It needs to be done right.
Whatever you decide to do, I think you are going to love this bike. Welcome to the forum!