*Check* to see if you need a new chain. Measure 12" of links under tension (have someone GENTLY stand on the pedal, just to tension the chain a bit). Align the 0 mark on one pin. If there is a pin at the 12" mark exactly you are golden. If it is at about 12 1/16", then replace chain but cassette is OK. If you are at 12 1/8" or past that you'll also need a new cassette and possibly chain rings.

How are the hub bearings? Bottom bracket, pedals, OK? These typically last much more than 3,000 but who knows.

Cables and housing should be FINE. Unless you feel any binding in the cables I wouldn't touch them.