de-codeing??

hi, need some expert advice, i just looked at a 16v turbo coupe that only has the silver key. The current owner has chipped the engine and said that the car has been de-coded and so the red key is no longer required. I meant to ask about the alarm system but forgot, does anyone know if what he say's is ok?? can you de-code the car to negate the importance and use of the red key?? does this affect the alarmn or the fault finding system. cambelt will also need changed very soon, does anyone know how much this will cost?

Yes what he is saying should be right.

Red key is NO use and is never needed.

Alarms are crap and need ripping out but are totally separate to the ecu system.

Belt should be anything upto £450, need doing every 32k.