I have been reading some alt Westeros theories that remind me of your economic plans- winter hardy cattle leads to a Tsarist North. One point puzzled me- a Moat Cailin canal makes Dorne mad since less trade but other than Braavos would it really make a difference?

That’s a bit odd. 

I don’t really see a mechanism by which a larger cattle-raising industry lead to Tsarism. 

And a Moat Cailin canal wouldn’t really piss off Dorne, because it’s more redistributing trade in the more northerly areas. So I would expect Gulltown to take a hit, King’s Landing to an extent, and maybe maybe Oldtown if more Lannisport trade goes north through the canal rather than south.