Any question answered...

The dart by standard has steep angles 75 st and 74 ht, with a road fork ~365mm axle-crown, cross forks have ~395mm axle-crown, after some googling a 30mm increase in axle-crown would push my angles to 73.5 and 72.5 or thereabouts, which would result in a more offroad/travel geo?

Can't fault that as the geo seemed normal, don't forget to account for the bottom bracket height which will be even higher if it's not high end already.

40mm rake fork should give it a nice road bike handling if you can find it, but then 45mm rake will be enough if you're looking at the Kinesis DC37.