What would you call a normal level of driveline noise?

You hit it on the head the bike is over ten years old would be very surprised and also very disappointed if Triumph did cover it.
 
Manic-Mechanic, THATS the word I was looking for, It feels like there is quite a lot of gear lash and very noticeable when gently applying and releasing the throttle at 1800rpm or less.

Remove the sump pan and check the rear screen. The gasket can't be but 20 bucks
If there is no bearing parts you'll feel better. My guess is there will be.

Yep, My 05 had it but not as bad as the 09. I've had the 09 for over three years with no other issues except the detent spring.
ALSO when my trans blew up due to a 50 cent snap ring, there was no sign of metal in the sump. Once I split the engine, there were gear teeth scattered all over. How none of it migrated to the sump is beyond me.
 
My bike doesn't make any clunking sounds in the drive line. Very smooth and quiet. The engine makes a lot of mechanical sounds but they are smooth and sound good to me.
 
My output shaft went out, and I ended up replacing the whole bottom end. Have it checked by the dealer.
 
I will get it in for a service asap then and ask them to check it out, then g̶e̶t̶ ̶s̶o̶m̶e̶ ̶p̶e̶n̶n̶i̶e̶s̶ ̶t̶o̶g̶e̶t̶h̶e̶r̶ rob a bank to cover the labour cost. Any recommendations for other jobs to get done while its apart?
 
I ended up replacing the shaft, hub, and the entire bottom end. While they were in there, the replaced the stator as well. It was about $5k, and I bought a used hub and shaft... but mine basically grenaded the bottom end, hopefully you caught it before too much damage happened. Good luck! There are engines out there if it’s too bad.