Are 'rattles' a valid warranty claim and dealership visit?
 

Sunroof rattle.
Rattle in gauge cluster.
Rattle in drivers-side door when music is on.
Rattle under drivers-side seat (I think its loose, it makes the clunk when you take corners)
Knocking noise (sound) at idle
Loose-nut sound on the passenger front area when going over slight bumps or anything less-than-smoothe

etc...

Will a dealership think I'm stupid for asking for these concerns addressed?

Hell yes it's valid, although some of these are going to be very hard to find perhaps. Write them all down as you have done so here, take the list in and ask that the Tech go with you for a road test. Sounds may change with someone in the passenger seat, so you need to see if that is true before you take it in.
And......................who cares if they think you're stupid.....you're paying for the car right? Things do loosen up over time and need to be re-tightened. Don't worry about going in for that stuff, just know it can be difficult to get them all on the first try.

under 12k miles definitely, after 12k it tends to be more difficult to get them to willingly work on it.