1995 Intrepid squeaking and grinding

I have problem with my 1995 Chrysler Intrepid (3.3L, 230,000KM). For about a month now I've been hearing an increasingly louder screeching / squealing noise from the front passenger side wheel well. When I first start out in the morning it's extremely loud, but seems to get quieter as I drive, although it never goes away. Sometimes while driving it will suddenly get very loud for a few seconds. It sounds a lot like a rock in the brakes, but it's been going on for too long. Applying the brakes doesn't have any effect on the sound, and it is not a belt squealing. My thought is that it's a wheel bearing, but I thought they made a grinding sound when on the way out.

Another problem is that sometimes when I apply the brakes I hear a horrible grinding noise coming from the front end. I can sometimes actually feel it in the floor boards. My brake pads seem fine (have about 1/4 inch left before the squealers). I think that it's probably improperly installed brake pads (they were on the car when I bought it) that are a bit loose and vibrate sometimes when I stop. Any thoughts?

Thanks!