Have to hold down handle when flushing

Well, I truely do know enough to be dangerous!! After replacing the seals in my shower faucets to stop a contant dripping, the hot water faucet now abruptly shuts off and causes the pipes to knock. I am certain that this is being caused by some adjustment I messed up when I was taking the hot water side of the faucet out of the shower. As a novice, I took a few too many nuts off on the hot side trying to figure out how to get it out and probably messed up something. On the cold side I knew that I just needed to take the whole faucet out to get to the seal and that one is working fine. Should I just go get a new assembly and pop it in to place or is there a simple adjustment on one of the nuts toward the outside of the faucet assembly that will fix my problem? Thanks in advance for your help!!

We have a Kohler toilet that recently has not been flushing properly. When you flush the toilet, the bowl begins to fill but does not goes down like it normally did. Sometimes the water will go down, others it fills the bowl and drains slowly. I have snaked the toilet 25 feet and tried plunging it, but because of the shape of the bowl, when you plunge it, the water squirts out of the sides of the plunger,(there is a contour in the bowl by the opening). After the first time I snaked the line, it flushed ok, but still drained slowly. Now it will flush ok one time then not the next. My father-in-law insists it is clogged due to something my 2 year old son put in the toilet. Is there anything else I can try before I have to call out a plummer? Will the plummer do something special that I can't do to make it work properly? Thank you