The only difference between an Admin and a standard account is that one is a member of the group 'Admin'.
You only need one account to be part of the Admin group so no there's no problem in making a new account to be Admin and demoting your own account to standard.
Theory behind it being that if something/someone were to get hold of your account while you were logged in they still can't do anything.
And although the Admin group aren't proper root accounts, they effectively are because they just tell the system to do stuff as root for them, and it obeys.
It's best practice to have two accounts and use the standard one, but hardly anyone does... I don't. I will next time I reinstall my Mac, but... that'll be ****ing ages