Various noises from my Titanium X

Ok so my 67-Plate Titanium X 1.5 Ecoboost Petrol Manual makes a couple noises I don't like too much. I'm wondering if they're normal and if not, what I can do to fix it.

I've got decent recordings of these noises but I don't think it's letting me upload them.

The first noise is a kind of pulsing grind. It's loud enough to be heard in the cabin and starts just after engine start. It happens at low revs and isn't too worrying but I don't know if it's a journal noise so I'm assuming the worst here.

The second is a knocking that seems to be coming from the rear of the vehicle. I think it's something to do with the seats, although there fix properly. The boot is empty, the share wheel is tightly locked by the sub, there are no lose items in the back and it's not anything I can see from the outside of the car. It happens when going basically any speed but obviously gets drowned out at higher speeds. I'm at my wit's end with it, I can't deal with the tiniest of rattles.

Speaking of which, how would I go about making sure my door trims don't rattle when I've got my music on? I've tightened the screw on the outside edge of the door card on both sides but I can still hear rattles! Minor, but they're there.

Thanks

Sam