They should spin freely. If it s bent or if there is any indications of cracks or stress areas, replace it. Clean and repack bearings once a year at least. Lube seatpost liberally with white lithium grease for proper operation. Use electrical tape on small tears.
Check rims for cracks, dings, dents, loose or broken spokes or other deformity.
Have all installations and repairs done by a professional mechanic.