Was also wondering about flock numbers and roof eave ventilation.
Pics of eaves (under edge of roof), inside and out, would really help.
Looks like there is a gable vent that could probably be opened up.
The 'chimney'
may help with ventilation.
The opening over the 'pop door' may be fine, or not(it needs 1/2" hardware cloth against predators tho). Some louvers would probably be good there.
Does that 'pop door' face your prevailing winds?
That ladder does not really look functional, do they actually climb up it or fly up and down?
Best way to 'test' ventilation vs drafts is to go inside on a really windy day and feel the air movement.Here's a pretty good discussion about:
http://www.backyardchickens.com/t/1048597/ventilated-but-free-of-drafts
Run is covered with mesh?
You'll need good framing to hold up a tarp(or anything) when it gets loaded with snow.
If you can't 'dry in' the run, you'll need to keep feed inside coop...and probably shovel some snow in the run, chicken aren't good with deep snow.
Is there power out there?
More light could be good, especially with that door closed .
You'll need to heat your waterer to keep it thawed, unless you plan on swapping out waterer multiple times a day.
Your video was pretty good, but sometimes still shots are more useful.
Some father back shots of the whole building would help.
It
is a very cool building!