I am a new plumber and the shower/bath at my new house is stumping me, before I go out and replace the guts its a moen single handle faucet wondering what could be the cause. The water pressure starts off good then slowly decreases. If I push the lever diverter and pull back up shower pressure is good again, then cycle starts over from good pressure to almost nothing. House has copper plumbing and is single story with a recirc pump.

Our toilet recently started leaking at the big main drain pipe just below it (which is exposed in the basement). I can see wetness dripping down the sides of the main pipe seemingly coming from just above (where the toilet sits atop). Coincidentally this began happening right around the time that I accidentally applied horizontal pressure to the toilet bowl in the bathroom, and it slid about 1/2-1" sideways across the floor- I noticed the nuts holding it to the bolts on the floor were loose, and I didn't tighten them right away which unfortunately let the bowl shift around on it's spot on the floor by about 1/2-1" in a few directions over the course of a week or so. Having replaced a toilet bowl once a very long time ago I vaguely recall a donut shaped wax seal being basically the only form of seal between the drain at the bottom of the toilet and the drain pipe in the floor. Now I am thinking all this shifting around may have smooshed the wax around enough to leave gaps in the seal... Can anyone think of anything else to look at before I pull it up? Thanks!!