I'll tell ya one thing; if you do the clutch, you NEED that paper gasket. I once tried to use gasket sealer and it left no clearance for the shifter to return, would end up hanging up on the case. Tolerances are that tight in a Nighthawk 450.I make my own, even clutch cover gaskets as I am poor. The clutch cover and flywheel cover gaskets, I glue to the cover and grease well. They are easy to make.
Its is not really necessary to remove the flywheel cover just to do valve working clearance checks and adjustments as there are 2 methods/indications of cam "setting".
However, yes, its good to remove the flywheel cover for your peace of mind.
If yours has the round slotted small cover at about 1 o clock on the clutch cover, smile, if not, get a new clutch cover gasket as well.
I also glue the cam cover seal in place. If your fighting to get the cover off and on, your doing it wrong.
Whilst the flywheel cover and cam cover is off, that's a good time to check cam sprocket "lean back" and chain lift from cam sprocket, as well as a cam chain adjustment and balance chain adjustment.