It can be confusing. The editor's Choice are the first ones you see listed and they are the top ten entries overall. You'll see some names in there twice because they will place in their level and overall. Sometimes, especially in Masters though, you may only see the name once. Since many of the Masters are in the top ten overall this week, I earned an EC, but didn't place in the top five of my level.
As for moving up, the rules have changed from a few years ago. Now you only have to move up if you win 1st place in your level or an EC. (not to be confused with an HC which means Highly commended and are 4th and 5th place in each level.) The exception is moving up to Masters. If you're in level 3 and you win 1st place, you don't move up. To be in Masters you have to win three EC's. It took me almost three years to get all three of mine.
So the first group of winners you see are the Editor's Choices and they will be published in the FW anthologies. Then it gets broken down by each level.
Later, after the winners bask in the glory (usually Thursday night, but sometimes Friday or later) Deb will post the highest rankings. This is to encourage people and let them know how they did in their levels and overall. Depending on the number of entries she'll post up to the top 40 overall and up to the top 15 in each level.
Once she posts that, I try to make sure I go through and leave a note on people's entries to let them know they ranked 6th in their level and 17 overall (or whatever they ranked) just so they know because not everyone goes to the message boards and so there is a record on the comments letting people know how well they did that week. Sometimes it's nice to see that on the comments when I'm looking over my old entries.
I hope this clears it up. You don't have to move up unless you place first in your level or are in the top ten overall!
Sometimes God calms the storm; Sometimes He lets the storm rage and calms His child