MK EMH 12/1 - how early to arrive?

A few ?'s based on my reading so far:

MK opens for EMH at 7AM! Will Main Street therefore open at 6AM? I would like to mail postcards from City Hall, pick up SOTMK cards, get a coffee and use facilities before we’re allowed on rides.

We are planning to walk from Poly to TTC to catch either Monorail or Ferry. What time would either of these begin running? Only on-property guests will be allowed to board these that early? Or are there special turnstiles at MK entrance to verify that you are staying on property?