I'd go ahead and proceed with dragging your files over to the new account and just deleting the old User1 account.
You mentioned Outlook files. You can drag those over also (the PST or PSO file that the emails are stored in). Or if your Outlook connects to any online email provider (like a company Exchange server or something like Gmail/Outlook/Live/Hotmail/MSN/etc), then you don't need to do anything. You can just add the account to Outlook in the new profile and it will sync all your mail again.
Of course you aren't in any hurry to delete the old account. So just use User2 and if you happen to come across something you need, you can go get it from User1. When you've done this for a few weeks you could probably go ahead and just delete the User1 account.