Just read something similar on the Civic forums which is making me think I may need to look into insurance covering this...
I also had a rock hit on a car about 6 years ago that initially didn't show up until I came back about 3-4 hours later. The car was sitting out in the sun so it had time...
With Hondata you can apparently see oil pressure on the DE5, but as others have said the oil temp metric is a calculation on the FL5 so you wouldn't see it. Think the oil pressure PID just isn't showing up with the typical OBD scanner stuff without specific indexing.
My car has the passenger door and center dash rattles as well. Rough roads make it more apparent and to some extent so far they're temperature dependent.