Wheel Bearings on a 7 year old pop-up - Shuld I?

Non-use can be more damaging than use. Things like tires and bearings are meant to be used.

Repack the bearings and replace the tires. Minimal expenses and will keep the trailer in service longer. Lots of good information and tips in other posts; check hub temps & tire play, watch for abnormal wear on the trailer, etc.
Happy camping!