Well it was supposed to be 5 gallons haha, but it wound up being about 3.5-4 gallons. I was aiming for a 1.065 OG and wound up with like 1.071. Not horrible, and I'll have to deal with the higher ABV, but I'm chalking it up to my learning curve and me still figuring out my kettle's efficiency.
I put the cinnamon in at about 10 mins of the boil. The head brewer at my local brewery suggested putting a stick in a muslin bag, tying the bag to a string and throwing it in. It worked out well. I put the molasses and ginger in at 15 mins, and the rest of the spices in at 10. I also put a small addition of Willamette hops in at 5 mins.
I think you may be on to something with the refractometer. Might be worth investing in for me too, since I'm still having trouble with my gravity.