Looks like a really good design man! Check em out. NSW makes really beautiful
cast iron stoves. Andrew makes each one himself one at a time, so there is a wait.. But he is also helpful with answering questions..
A 6" pipe is probably a easier pass with insurance guys but i don't know if that would draw right..
I'm interested to see what a "pro" would say about your interesting build.. My buddy is interested in making his own stove too. I have a NSW-2 little cod but haven't fired her up yet. I bought her while I was planning my own tiny house build, now I'm buying a small house with
land in the town I grew up and close to work.. Still love the stove though and plan on having installed one way or another.
Good luck!