Unlock sprint BB 8830 world edition

I bought BB 8830 world edition phone from Sprint. Sprint markets this phone as an unlocked phone and provides a SIM separately.

My first question: Is this phone really unlocked and can be used with any SIM provided by any service provider in India (CDMA/GSM)?

I want to use it on reliance CDMA network. Reliance website supports this phone. So first, I'll try taking it to a Reliance Web World and try asking them first.

My Second question: If its not unlocked, can somebody help me in unlocking it so that I can use it with Reliance and/or Vodafone?

My Third question: After unlocking the phone is this phone's usage limited to any one of the technologies i.e,. will I be able to use it either with CDMA or GSM or after unlocking it I can use it with any of them at any given point of time?

My Fourth question: After unlocking the phone, I want to use the Blackberry Internet Services... Will this be possible after unlocking the phone?