I have 2 icons that look the same, like little envelopes, one is labeled messages and the other is my email address. Does it matter if you hide one? It drive me crazy to see the exact same thing twice.

the messages one is for email, pin and bb messenger (basically whatever isn't sms or mms) so if you hid the email one it wouldn't really matter if you don't mind seeing your emails mixed in with the other messages

The 'Messages' icon contains ALL email, as well as PIN, SMS, MMS, and call logs.

If you had 2 different email accounts setup for your device, you would have 3 icons: 1 for messages, and 1 for each different email account.

Thank you