It's not really a "bad" idea. It's good to have a second account for trouble shooting purposes but your admin account still does not give you access to anything that can really eff up your system For that, you would have to enable the "root" account. If you want another account, just set it up and then copy the folders in your admin account (not the account or "home" folder itself but it's contents) and paste it all into the account (or "home") folder in the new account, overwriting the existing ones. Your new account will then match the existing admin account.
