Cartridge/tonearm shaking and other questions

Forgive me, I wasn’t sure how to capture my questions in the title of thread but I hope I can explain my issues and get some advice. I also think my questions are general in nature, regardless of the model and someone has probably run into these before. The first issue I have is when I turn the volume up very high, even with the tonearm at rest, if I tap on the tonearm I can hear the tapping noise from the speakers. I checked the ground wire and it is tightly connected to the preamp. The second issue which may be related is sometimes, as the record is being played, the cartridge assembly starts to vibrate even with the volume completely turned down. This happens on records that are completely flat and clean and can get bad enough to cause momentary skips and then calms down and all is well. I have owned several turntables in the past but have never run into the vibrating cartridge scenario before. The tonearm noise I just happened to notice when I was moving the tonearm to the next track with the volume real high otherwise I would have missed it. Thanks in advance.

P.S. I should add this is all related to a new (to me) turntable I recently picked up and covered in a different thread.