Sounds great! I did something similar with my nut brown, but didn't get much flavor. Based on my experience and reading here, I would recommend using the maple extract instead of syrup - the syrup won't contribute much if any flavor whether you use it in the boil or prime with it if you are bottling (and it is expensive). As for the vanilla, I used 4 ounces of good quality extract and you cannot taste it, I've read that vanilla is best done by putting 2-3 scraped beans in a secondary for 4-7 days. Cinnamon can be done in the boil or secondary.
Hope it turns out well, sounds fantastic!
On Deck: CaliCommon, Amber, Wit
Primary: Munich/Cascade SMaSH, Dubbel
Secondary: Petite Orange
Bottled: Blé de Minuit, Belgian Stout, Fuller's London Pride, Tripel Wit, Red, APA, Dubbel, Oatmeal Stout, RIS, Wee Heavy
Kegged: APA, Doppelbock, Spiced Cider, C3IPA
"Beer... Now there's a temporary solution!"