engine noise(s)

Ok guys... as some of you may know my car has 168,000 miles on it. I picked it up late July this summer from the back lot of a car dealership at a wholesale auction. I knew it was pretty rough and had been mistreated when I got it but I figured what the hell, can't go wrong for $2,000. Anyways, there are a collection of concerning noises coming from the engine. First, there is a metallic rattle kind of sound that reminds me of a bearing spinning with a broken race that I believe is coming from the water pump. The belt squeaks a little especially when cold even though it is tight which leads me to believe there must be a decent drag on it. No overheat so far but it does seem a little warmer than it did in the past, even though it is cooler outside. Next, I have a ton of lifter clack, which I know to fix that all I need to do is adjust the lifters. And finally over the lifter clack at engine speeds around 1,000-2,500 there is a rather pronounced tapping sound. It is a deeper and slower tap than the lifters. I have a feeling it may be a rod knocking. All of this makes me think I have a time bomb engine waiting to go off. If only I knew how much longer she would run I wouldn't be so concerned. I was considering selling the car and getting a different one I found but I can't really do that now. First of all I can't collect enough money to pull it off and second I just wouldn't feel right selling a car when I think it could go boom any day.

Anyone got any thoughts/advice? Anything? :disappoin