2001 Blazer LS 2wd 4.3

I bought this car a few months ago, and ive been having problems with it shaking at high way speeds, 70-80 it shakes really bad. I took it to belletire to have them check it out, they said that my wheel bearing on my front drivers side is bad.. im not too sure when it comes to these things, but will a bad wheel bearing make a car shake so bad.. also how can i, on my own, check to see if its bad?

Also, theres more to my problem, when im driving above 15, if i keep on the accelerator, no click. if i let off the accelerator, i hear a constant clicking sound, like a tick tick tick in the rear of my car. the faster im going, the quicker the click, the slower im going, the slower the click. i noticed by rocking the rear of my truck i hear the clicking but cant pin point it, any idea what my problem could be? Thanks in advance!