What time should we plan on being at the gate? will we have a problem getting in since it's extra magic hours? I was planning on getting us to the gate around 7:30 (probably by cab)
Are you staying on-site? If so, you shouldn't have a problem getting in. I believe that if you not staying on-site and it's and EMH, you will not be allowed in, even if you have an ADR.
You should be able to get in even if you are off site. They check for Resort Cards at every ride, and entrance to stores. So it's not like you can do anything. Not 100% sure of course. Just my thoughts;
I recall there being a CM or two at the turnstiles with a list of names and ADR times. As long as you have a ressie for breakfast it shouldn't matter if yu are staying on or off site.