I just got the rebuild kit for my Rear pbr calipers and have a couple of questions.
-The kit came with a small plastic bottle with a clear fluid in it and a packet of white grease. what do i uses these for?
-Also the bore on one of my calipers is nice and smooth as one would expect but the other one is kind of rough. Is this a problem? I bought these calipers from a wrecked 95 and only rebuilt them because I was disassembling them to powder coat. As far as I know they worked fine before.

The clear fluid is hydraulic assembly fluid, used the lubricate the piston and seal as you reassemble the caliper. The white grease is probably for the parking brake mechanicals.
A rough bore can cause binding and premature wear as the piston can get hung in the bore. Unfortunately, with an aluminum caliper it is hard to remove such roughness and if you did it would probably leak. If you use it check for exessive inboard pad wear every 3-6 months. We never reuse aluminum calipers with damaged bores in my shop. Too many leaking problems!!