weird noise from water pump?

[SinceByMan]

I just had my water pump replaced and before it was replaced my car would make an odd noise after I had been driving for a while, like 30 min to an hour. I dont know how to describe the sound, its like a hissing noise and it sounds like its coming from the water pump area of the engine, the front cover.

on another note, I have the nefarious timing chain rattle and sometimes it is most pronounced at a certain RPM, the specific RPM varies but my question is, sometimes I will be doing like 2300 RPM for instance and the timing chain will be rattling, I usually speed up to quiet it because Im guessing that when it rattles that is wearing the chain. Is that right?

again on another note, sometimes I cant start my car unless I put my foot on the gas, or it will start but then sputter and die and I have to give it gas for a few seconds until it can idle on its own, what causes this?

sorry for the length of this.