3. I think Dick is the new Batman. If that is the case why didn't Tim just become Nightwing instead of Red Robin. I mean is Kingdom Come that popular?
Because there's a Nightwing running around the Superman books -- Christopher Kent, Superman's adopted son. So the name's been retired from the Batman books so it can be used in the Superman books, which meant that Tim was going to need a new identity.
If you're reading Red Robin
, Tim's use of the identity actually works. Tim's having to go outside his usual channels, and there's no preconceived baggage around the Red Robin identity. This also helps him when his cover gets blown, as the character in question has no idea that Tim isn't anything other than a League of Assassins member in fancy garb.