Sox fan here, but I can answer your question.
The boat that goes directly to the MK will not depart until roughly 30 minutes before opening. However, there is another watercraft that runs the WL/FtW/Contemporary circuit. Hop on that boat to the CR and either take the walkway to MK or jump on the monorail. We prefer the walkway - it takes about 8 minutes to walk from the front of the CR to the baggage check at MK.
Yep, you just need your ADR # and your last name.
CP begins ADRs at 8 am . . . one hour before park opening. I know Chef Mickey's starts serving around 7 or 7:30 am.