Ecoboost Issues or nitpicks?

So I'm not sure exactly which these are. I've seen many complain about transmission "noise" but I never really see it explained. Hell some are even going through lemon law cases for it.

First: When moving fairly slow, below 20 say, When I push the clutch in (with no gas) It sounds like the driveshaft bashes back and forth. It can be felt through the shifter, clutch and the floor board. Feels like it's bouncing back and forth (Probably from slack in the drivetrain). Anyone had any problems with this?

Second: I'm not overly familiar with the "4 cylinder turbo" scene, but it feels as though it's extremely....grindy/geary. It's an exceptionally hard sound/feeling to explain. Not like vibration but more like...notchy while driving. Doesn't SOUND smooth at all. Like you can literally pick out the revolutions audibly. I can't tell if it's an engine thing, or transmission. But my MT82 in my S197 was silky smooth compared to this. It's like you can hear the individual gear teeth engaging each other, and you can definitely feel it through the clutch/shifter.

I feel like the second one may just be a 4 cylinder thing? Although it feels/seems to be more transmission related. Sorry if I seem paranoid, but after going from one failed mustang, I really don't want to get into another :(

For the first one, I always thought that it is the clutch chattering (when suddenly relieved of the load from engine/engine-braking). I have a manual V6, and I experience this a lot (esp. when coasting out of my drive way (no gas) and then step on the clutch).

I'm sure the first issue is a culmanation of multiple things. 2piece flywheel, driveshaft, clutch etc. I was just curious if excessive movement would cause any issue down the line. Seems like it bouncing back and forth like that would create extra stress. My manual V6 NEVER did it haha