Turek,
First, I want to mention that I'm definitely interested in where this is going. Please keep writing. I'm not as interested in the actual military history of the war itself than I am in the social developments afterward (for example, do the Acadians return? What does the State of Acadia look like demographically? How much does it integrate into New England, and how separate is it, etc.), but I'll read the military history you're writing.
Secondly, I want to mention that, as someone who grew up in Halifax, I'm very familiar with Nova Scotian history, and could perhaps offer you some pointers/fact checks. I have a couple already that may result in minor changes in your TL:
1) From what I recall, the main reason that Nova Scotia didn't rebel in the American Revolution was that a LARGE portion of the population at the time was British military-affiliated (not all soldiers, but in occupations that directly supported the base in Halifax). It seems that you've taken that into account, and the small number of Nova Scotian revolutionaries does reflect that. One thing I'm really interested in is how the Americans settle the area once the British military pulls out.
2) I'm not sure what the Natives that are fighting are Maliseets rather than Mi'kmaq (aka micmac). While there are some Maliseets in what is now New Brunswick, the majority of the natives in the area would have been Mi'kmaq, the Maliseets are only present right along what is now the Maine border...
3) At one point you had the army marching from Fort St. John to Fort Cumberland. As far as I know there was no road back then traversing that route (although there may have been a military trail?? not sure), and they likely would have had to travel by ship.
4) If you want any help in working out how the Battle of Halifax goes, one of my obsessions as a child was in studying the fortifications in my hometown. As far as I remember, the defences in the 18th century were considered impregnable, although if the ships arrived under false flag, they could have maybe made it past the outer defenses... Also, from what I remember there wasn't much of a "city" in 1776 (Halifax was only founded a generation earlier in 1749), it was mostly a military base, although of course there would have been enough of a city to support the base.
Keep up the good work, and don't get discouraged!