I see in the rules about the multiple accounts for the purposes of botting, and actually quite glad that's there. However, I couldn't find anything about having an account for a different realm. And no, there is no intentions of using 1 account as a spy for the other. After playing DAOC (Live) when the free month for returning players was available in the summer I played for a couple of months there and kept bouncing between the different realms to try to find which class appeals to me most. I did find the class I enjoyed the most there, but mainly because of the ease of leveling and lack of AT'ing was far different there than back in classic. So, I'm back in the whole trying to find which class/realm appeals to me all over again.

The question:
Am I allowed to have an additional account for a different realm than the one I originally picked a long while back on my current "main" account?

You are only allowed to have ONE Master account. If you click on the "Manage Account" you find a folder "Realm Transfer"
there you can switch your realm with a 7 days timer.

Please note that a realm transfer takes 7 days from the time it is started, and you cannot log into your account for the last 8 hours of the transfer. Cancelling a realm transfer will not stop the 7-day cooldown timer, but will prevent your account from changing realms. If you want to switch realms immediately, you can always do so by deleting all characters in your current realm.

Switching realms will never delete your existing characters. However you will not be able to log into any of them until you switch back to your original realm.

Thanks for the Info.