Traditionally our MK EMH approach has been to start at Space, then go to Buzz, do a few other things (choosing from Speedway, Pooh, Dumbo, Barnstormer, Teacups, Astro Orbiter, Mermaid) before the regular park open. Often we go to PP about 20 minutes before the end of EMH and ride that so we are in a good spot to enter Liberty Square when that opens. We have usually found the posted wait time to be about 15-20 minutes and the actual wait a little less than that at that time. The Rapunzel area is also a convenient spot for a quick pit stop before heading to the rest of the park. When the park opens to everyone, we will hit HM, Splash, Thunder, POC, and Jungle Cruise (in some order) before the lines get too long. We have had pretty good luck going to Splash and Thunder first, then POC and JC, then cutting back through the breezeway to HM.
Now that 7DMT is open we would probably do that first. We have done 2 AM EMH since 7DMT opened, and by arriving about a half hour before EMH opens and setting up on the right side arch, we have been able to do 7DMT with virtually no wait and, after getting off, proceed to Space and Buzz as usual. On those 2 visits, I have observed that the rush to 7DMT has significantly reduced the number of people who start at Space, which always used to be the most popular EMH starting point.
Based on what you listed as your priorities, I would start at 7DMT, then go to Space, Buzz, and the Speedway and then see what time it is to see if you have time for anything else. If you skip 7DMT you will be that much further ahead. As 9 AM approaches (for an 8 AM EMH) you will want to be in position to enter Liberty Square or Adventureland so you can hit the other mountains and the other major attractions on that side of the park as soon as they open.
Peter Pan is a good choice for a FP because the line there builds so quickly.
AM EMH at the MK are great. I think you'll be pleasantly surprised how much you can do before 11 AM, so I wouldn't schedule any FPs earlier than that.