I'm just wondering what the current plan is for multiple starting scenarios.  For example, I'd like to have different scenarios for 6-player FFA and 2v2v2 or 3v3 teams.  Starting locations and unit counts would be different.

That's definitely part of the planned functionality. Once I'm done with a round of general bug fixing and minor updates I'll set up a vote for the next major enhancement.

Multiple scenarios shouldn't actually be that large a piece of work, certainly nothing like as large as the tournament system.

I'll be voting for this.

I would like to go one step further also and be able to specify a game for certain numbers of people, but not a range. In particular I am working on two boards - one could be played 2 player or 4, but would be awful with 3 - the other would work with 2, 3, 4 or 6, but not 5.

The reason for this is there are starting positions, and with 1 less then the total one person would start off by themselves while the other people beat on each other.