This is EXACTLY the ideal post that I feel this forum was created for.
Within ALL the previous posts, I'm convinced that you will find your answers. So, as well as waiting for the 'expert' answers :-& from the rest of us.
Firstly though, if you are asking for specific answers then the more information you can give , the better able we are to 'target' our responses to your specific inquires.( I.E you havent told us the age group of the team...I gather it may well be a fairly young team).
I've always gone with the idea that you put your BEST 7 players in the formation of GK followed by 2 good centre backs, 2 good middle players directly in front of the 2 good centre backs, and 2 fast forwards directly in front of the 2 middle players. This hould create the 'spine' formation and the other players in the formation assist these 7. ( there are lots of previous posts on this subject..happy hunting mark).
Keeping positions and maintaining shape are challenges to be solved in training first. Again there are very good posts on these topics to be found within the pages of this forum site.
Indoor soccer is a different kind of game to outdoor. For one, the climate is not an inhibiting factor, and the playing surface must be taken into consideration in your practice drills etc.
Have you tried Football de Salao ( the brasilian form of indoor soccer??). This is a GREAT game for teaching ALL the intricate dribbling and one touch skills so sorely lacking in a majority of younger players today. Remember there are NO bad pupils only Bad teachers.
Good luck MarkD with your 'discoveries'