Undo Migration Assistant work

I have a macbook pro. I also have an iMac (a few months old). There are two users on the macbook. Last night I decided I wanted to copy my account from the macbook to the iMac. I turned off the macbook and connected the two computers with the firewire. (before doing anything, I did a time machine back up on both machines) I logged into the admin account on the iMac. I turned on the macbook and held down the T key. I got the screen with the firewire symbol on it. On the iMac, I opened the migration assistant. I told it that I wanted to import a my username (not the admin account). The transfer of 41GB took about and hour. When it said it was complete. I tried to find the new username and found nothing. I restarted the computer. When that happened, I got a log on screen that has renamed the computer as the macbook pro, but left the other username on the computer that was already on it. Also, the wireless keyboard and mouse did not work. My questions:

1. Is there any way to get the wireless mouse and keyboard to work without a wired one?
2. Since I did a back up, I am guessing that I can just restore the iMac to the way it was prior to the import, and then figure out what I did wrong and try again.
3. What did I do wrong to make the migration assistant not work?