You can estimate your OG if you want to do the math. A pound of honey will raise the gravity of water by approximately 0.035. You need a rough estimate of how much water you actually used.
I don't know why you couldn't use oils if you could control the strength. Citrus zest is mainly oil, but not as concentrated. I have used lemon and orange oils when back sweetening, with success. I don't think the root beer would be a good one to start with though.
I haven't started it yet. I have the ingredients, waiting on a stockpot. I didn't want to steep in batches. I'm making what will be 6+ gallons. I'll let you know!!
Two more clarifications, if you don't mind. First, light or dark brown sugar? And second, how long were the cinnamon sticks to start? I have 4" and 8" sticks.
thanks
Dennis