MLK weekend is not partiularily busy as it's not a 3 day weekend or major holiday for most people. Don't take this the wrong way, it's a weekend and all weekends are busy. There just really isn't anything special about it.
Each FL attraction will take about 7.5 minutes and with a dozen attractions you can't get to all of them in an hour. Plan to do Peter Pan, Matterhorn, Mr Toad, Dumbo and Tea Cups and maybe Small World, becuase they have longer lines later in the day. Small World lines would be third on the list but because it's a ways away it may not be one to fit in.
For Toontown Madness and DCA it may be possible. You could do Mickey's Toontown Madness on Friday if you are there. Or save the early entry into DCA for a day other than Saturday.
To enter DCA at 9:30 it's quite simple and not a must, but helpful.
You go in the front gate that open at 9:30. You can at this time ride Soaring(takes about 10-20 minutes.) You can get Soaring FastPasses. You can get a World of Color Show Pass. Maybe ride Mermaid, how this works may change. Also line up for the Rope Drop into the pier area.
The rope drops at 10am with most guests going to TSMM, CS and MFW. If you aren't at the front you will likely to TSMM when it already has a 10-20 minute wait. If you are a few minutes after wait drop it will be a 30 minute wait, and be 30-45 minutes the rest of the day.. So it's a trade off wait at rope drop for 30 or 25 minutes. Or wait for TSMM 30-45 minutes.