I told the plan I’ll be in MK from 7:30am till 1am. I don’t understand why it’s putting a 344 minute gap between Chef Mickey and the next attraction inside MK.
Granted, I used “optimize” but why would it not spread out the remaining attractions out more instead of cramming them all between 6:55pm and 1am?
Large gaps in time usually tell you that you have too few attractions for the time. Add more attractions to your plan, or reduce your park time might work.
To expand on that answer, optimise is intended to give you the shortest total wait. Waits are shortest in the evening so that’s where it will often put attractions. If you’re happy to have longer waits, put things in the order you want and then evaluate. But it sounds like you’re going to have a fair amount of free time anyway. Try putting in breaks to take up some of the free time or maybe repeat rides, or as @PrincipalTinker said shorten the hours of your plan.
I’m confused by your statement. Are there more steps in your plan than what you have shown?
It would appear that you have 6 Flexible Start Time attractions (steps 1 → 6) and 3 Fixed Start Time attractions (steps 7-> 9). The Optimizer has placed the 6 Flexible attractions in a manner that aligns with your first Fixed attraction (step 7) and has nothing left to schedule between Fixed steps 7, 8 & 9.
I don’t see where any Flexible steps were crammed between 6:55P and 1:00A.
Yes, my plan is packed with everything we want to do. I’m just surprised it choose leaving a gap like that over having us be done early. Some of the attractions are scheduled for just a few minutes before closing.
It will eliminate the gap if you set your finish time earlier 
(or, conversely, start later)
What she said! (Not to be confused with “TWSS”.)
Remember, the algorithm is trying to optimize for shortest wait times and/or shortest walks by using the total time you specified that you will be in the park. So, if you specify all available park hours, it has all those hours to work with, and picks the times that best minimize waits/walks.
If you really do NOT want to be in the park all day, and you don’t have enough to fill the day, you need to adjust the hours you DO want to be in the park.
If you are a “rope” drop kind of family, then try eliminating, say, 5 1/2 hours from the tail end of your day and optimize. If it says you can’t get through everything, keep adding an extra 30 minutes to an hour and optimize again until it gives you a plan that fits into your allotted park hours.
If you are a “stay until close” type, then do the same, but eliminating hours from the START of your day.
There are other ways you can do it as well. That’s half the fun! 
