Leaking CV boot and noisy brakes

Concerning a 2000 golf with 70,000 miles

1) I took my car in for #2 below the mechanic said I had a small hole in an inner CV boot. He figured it would probably take a few thousand miles to leak to the point of being a problem, and it was fine to replace it then.

Does this make sense?

2) Last Friday I started having an intermittent rubbing/grinding noise from the right front wheel. On Saturday it got so loud, for about 30 seconds, that my 11 year old was concerned. It seemed to stop when I touched the brakes. The mechanic found a right REAR brake pad had worn at a decided angle, and was worn to the metal on one side and damaged the rotor. The other three pads were worn, but had plenty of miles left in them. He did not know why it was like that; as the brakes seemed to work fine. He thought that whatever the problem was, taking it apart had freed it up.

Does that make sense?

He recommended replacing all the pads and rotors. The pads come in sets of

4 and have to all be replaced at the same time. The rotors could be turned, but he thought it was false economy to save $50.

Is this correct?

The noise is gone; but my son and I were sure it was the front wheel, not the rear.

Are noises like that deceptive enough to fool us, or was it unrelated to the brake pad?

Thanks; just wanting to ascertain how good a shop I am using.