retrofitting a wood stove to heat water

[glenn kangiser]

I think you are likely right.

[MountainDon]

On thinking it over and seeing your drawing I'd guess that the point to point plumbing is fine, but the thermosiphon action might be slowed down by the height limitation for the tank and all those 90 degree turns. 

How hot does the hot pipe from the stove to the tank get?

A very small circulation pump would likely do wonders for evening out the tank temperature.