If two things are directly related, it means that changing one will also change the other. If they change in the same direction, they are proportionaly related [yoke position to elevator position]; if they change in opposite direction, they are inversely proportional [altitude to blood oxygen level]. If changing one will make some sort of undefined change in the other, then it is an indirect relationship. This is my take after too much Engineering Math in college and years of non-academic experience. It may be "not fully true" in the way that drives my Math Professor cousin crazy, but that's her problem.
As for flying through turbulence, I once read a good description of the various amounts. From memory:
-light turbulence will make you spill your coffee
-moderate turbulence will make the stewardess spill your coffee
-severe turbulence will spill the stewardess
Applied to my Mooney, if it's much rougher than driving my car down a dirt road, I'll slow down some. If things are shifting around inside, if my wife is bouncing off the ceiling, if the wings are flexing an amount that I don't like, I'll pull back below Va [for my C, 132 mph at gross, going down an undefined amount with weight reduction]. So far, I've managed to avoid turbulence severe enough that reading the gages or GPS is difficult, and I've not bounced the wife very many times.
For scale,
60 mph = 88 feet per second = 5280 feet per minute [fpm on your VSI]
500 fpm = 5.7 mph [approx. 100 fpm = 1 mph vertically]
But speed alone won't bump you into the ceiling, that takes acceleration. How fast is your speed changing by 30 or 50 fps? Zero to 30 fps in ½ second is quite a different feeling than level flight to 1500+ fpm in two seconds inside a cloud. "Acceleration" is a measure of how fast your speed is changing, conveniently measured in g's, while 30 feet per second is just a speed.
Happy flying, and try to avoid clear air turbulence. For what it's worth, I descend with MP and EGT at cruise values all the way down unless it gets rough; then I level off to bleed speed, reduce throttle and descend at a lower IAS so the bumps aren't as harsh.