Valvetrain weight vs. RPM limit

To me the cams ramps and spring pressures make more of a difference on valve float than the valve train weight.
The cams ramp speed will put tremmendous inertial force
on the components.
If you don't run lash caps, does the rocker ride off the center of the
valve stem?
Some good reading on valvetrains. This is a pdf file.

http://www.grapeaperacing.com/GrapeApeRacing/tech/valvetrain.pdf