Man, your heart is really in the right place and I really like the idea of the Riddler using the Internet to communicate, but you NEED to study the character. Here are some pointers:

1. Edward Nashton (alias Edward Nigma, alias The Riddler) has Obsessive Compulsive Disorder, not Multiple Personality Disorder. He doesn't write his riddles because one personality thinks the other is weak and wants to prove superiority, he does it simply because he NEEDS to. The Riddler is obsessed with puzzles and games because he NEEDS to prove he's smarter than other people and he NEEDS attention. It comes from having an abusive father who didn't recognize his intelligence. Also, The Riddler has a guilty conscience so when he writes riddles that lead to his crimes, he's subconsciously begging to get caught.

2. The Riddler is not The Joker. Please don't play him as such. I know that Heath Ledger's performance as The Joker is big in the public eye right now, but your performance of The Riddler is just too much like his performance of a totally different character. Study some comics with the Riddler in them, watch all the episodes of "Batman: The Animated Series" that have The Riddler in them, learn how the character acts.

Alright, there is my constructive criticism. I think you've got a great plan in mind, you just need to iron out the wrinkles.