While it's nice to have details .... like jkirk said ... long post.

Just skimmed over it and a couple of things come to mind ...

1 - you might be overstating the snow loads a bit
( as mentioned I just skimmed over .... when i get some time I'll review your figures)

2 - I would have to guess if your local building codes are similar to here .... since that deck is over 2 feet above ground and it's an attached deck you probably require a permit.
If so then the piers and footings would have to approved / inspected as well the deck design would have to be approved and inspected.
If you have doubts contact your local building department to come on site to check things out...... they would have answers to all your concerns.