yeah, im guessing its probably easier on a mechanical keyboard compared to a membrane. But i dont do vibro so what do i know.
Guy in vid seemed to vibro alright on a membrane, so its probably just a matter of practice and finding a technique that works for u https://www.youtube.com/watch?v=c0oMVPBhXDc
Depends but usually yeah from my experience it takes your speed down and increases stamina requirements so I guess you could compare it to training weights but they aren't necessarily hard enough to make a difference bigger than a dan or two of skill