I have badly corroded and chipping brass fixtures in the tub, The contractor suggests tearing it all out! Tub and tile are fine,, can I replace those fixtures and faucet... do they come off? Can they be refinished? I hate the thought of a jack hammer inside my house!

Jet and trim covers, also referred to as "trim" are usually purchased separately. You can purchase new trim set and install them over the jets. Costs lot less than replacing whole tub.

I have badly corroded and chipping brass fixtures in the tub, The contractor suggests tearing it all out! Tub and tile are fine,,,can I replace those fixtures and faucet...do they come off? Can they be refinished? I hate the thought of a jack hammer inside my house!

Your contractor should have told you to click on; Jacuzzi Parts S - T - Guillens Enterprises (http://www.guillens.com/jacuzzi/jacptss-t.htm)
Where you will find factory replacement trim. Never tear out and rewplace what can be repaired. Good luck, Tom