Ahhh! It looks great! Looking at your pictures it seems you had trouble in the exact same spot as I did, between its mouth and front leg, but looks like you made it through alright. What'd you end up doing for eye-holes?
I tried poking a bunch of pin-holes so they wouldn't be visible, but since it wasn't up close to my face, it didn't really work. I usually let in sit on my ears so I could see, until someone took a picture or something. When we did the actual walk my boyfriend held my hand and I looked at the ground, lol.
Depends on your intended use; for any sort of handling (i.e. cosplay), a heavier cardstock will be more durable, but harder to work with. For display purposes only, regular copy paper is easier to work with, but fragile.