So a couple of things:
1) the colour of transmission fluid is not a reliable indicator of condition on its own on modern cars;
2) don't take a brake diagnosis form a lube tech (they re not mechanics, hell half the time they're just kids);
3) I've never heard of brake fluid causing a grinding sensation so really not sure how that might alleviate such a symptom; and
4) pulsating/grinding/judder in brakes is most likely caused by uneven pad deposits and is more likely to be felt from issues with the front brakes...sometimes you will only feel these things once the brakes are warmed up more

at this point you've done a lot of random fluid/part changing on unrelated systems, maybe consider posting a video/sound clip of the issue as your description may not be translating well...

also since you're casting such a broad net here,is the symptom more apparent when you turn the wheel left to right? It could be the front wheel bearings, they commonly go out on these cars an cause vibrations....
if its happening while your moving at certain speeds it could even be a wheel wit ha flat spot or out of balance..but again your description seems too vague

 

I did think about front wheel bearings, but from what I've been told wheel bearing problems would normally get worse the faster you go. My issue is mostly noticeable when braking. I would say that I sometimes feel a little more "sensation" on curves or highway ramps. Maybe it's possible that the braking puts a load in a certain direction on the bearings where the bearings are more worn out. What's a good way to check wheel bearings?

 

check the wheel bearings by turning the wheel from side to side as you drive and listening for the noise and with the wheels off the gorund by putting your hands on the 3 and 9 o'clock postion of the tires and checkign for play...heres a video https://www.google.com/search?q=whee...Xm-gTH0pigBQ28

again you should post a video of your symptoms otherwise its a lot of shooting in the dark and confirmation bias going on