Nope. US.
Incorrect. You have to register for an account and have it approved, but once you do that you can check out online. No where does it say that you have to use THEIR shipping supplies. It only says "Approved Shipping Supplies", and I doubt they'd have any argument with the kits from SYR. The item in the cart is a FedEx Label. I've attached a picture for proof.
It's for Priority Overnight as the attached pic shows.
I'm shipping four snakes, so yeah, I think the box size is appropriate. The weight is a guesstimate based on the combined weight of the four animals and a stab in the dark on the weight of the packing materials.
Note: Though it says "Please Add Shipping Box" it lets me go all the way to PayPal without doing it.