I pretty much disagree with all of this.
1. I vote for something I want, but I can see that I'm the only one that wants it. However, something I really DON'T want is leading the votes. This allows me to change my vote to some alternative that is more palatable if anything else has a couple votes.
2. My understanding is that the uppermost option is chosen based on frequency/percentages like the previous Halo 3 playlist system did. (Some map/gametype combination appears X percentage of the time as the chosen default). The uppermost option is what the system thinks should be the next map based on whatever criteria they use - such as map and gametype percentages, etc. If I'm distracted (in the armor menus, settling a crying child, going to the washroom) I'd it goes to the default chosen by the system.
3. Same as 2.