1996 Jeep Cherokee 1996 Grand Cherokee - noise and vibratio

Hi, hope this is a simple problem! My 1996 Grand Cherokee has developed a vibration in the right front wheel. It starts at highway speeds around 45mph, and goes away around 60 mph or so. It is more apparent in 2WD, seems to vibrate less in 4wd. It also seems to vibrate less when turning right. Since this started, the right front tire has become much more worn than the other three. Also, I hear a soft rhythmic scraping sound from the right front at very low speeds (from 0 to maybe 5mph) - the rhythm seems to match the rotation speed of the wheel, and this sound started a month or so before I noticed the vibration.

I've called four places and received four different answers. Before I take it to a mechanic, does anyone have any ideas?

Thanks!!!!