Good to go for a big batch so early. I wouldn't add either the brown sugar or maple syrup to a barleywine. That does seem like a bit much for hops too. I'm assuming you are going to use the NB for bittering and the Perle for flavor/aroma? I know with the higher alcohol levels you can have higher IBU's, but that does seem a tad much. Just my opinion, though. I've made a barleywine before and used 2 ounces of NB for bittering (boiling for 90 minutes) and 2 ounces of a low-alpha hop for flavor/aroma.