With the tyres, yes it could be the OEM Yokohamas but generally the NX is louder inside anyway.
Connected services - for me, no its not worth the effort. Even the traffic updates are unreliable and I haven't really used anything else. Connected services are a work in progress to be honest and I think they need to start putting some actual connected services in, like remote starting and warming up the car when cold via app etc etc.
With the rattle, yes could be from the number plate rattling as the subwoofer is on the hatch. I would get some sticky pads of the foam variant and put them on each side of the number plate first along with the screws