Question about custom forms and cck dropdown propagation in Drupal

Hi all,

I've used Drupal to build sites for a few years now and I have a quick question about some functionality I want to implement using only existing modules without heavy modifications.

I'd like to create a form for different girls 'coach pitch' and 't-ball' teams, so that each year, when new teams are created I can add them to a database. I would then like to create an event calender (using calendar/date modules) that displays the filtered results on a specific page. Basically, "Team A" would have a link in navigation that takes them to a page with an event calendar specific to their team. I don't want the filter exposed because I don't want the parents to have to try and use it (simple as that may seem to us), just a static page with prefiltered results for each team. I also want an unfiltered calendar (for me) with every teams events in a single calendar.

I have played with this and created an event type with a 'team name' field that works well except, team names have to be set up in advance currently (select list), and I want that cck field to propagate from the teams that have been submitted. If a team merges, folds due to too few players, or gets a new sponsor, I want the dropdown list in the 'team name' field to change, and I am not sure how to do that or if it is even possible without a custom module.

I'd like the dropdown to propagate with the names of the teams automatically so that only the currently active teams are available in the dropdown list. Previous year's teams would be unpublished and unavailable (in theory) and saved in case that sponsor returns in a later year. When new teams are added, often in the middle of the year, I'd like them to become selectable in the 'team name' dropdown field when creating new events.

Obviously, this would be easiest with Organic groups and groups calendars; however, that would require (i think) the children's parents to sign in and create accounts, and I think that is probably more than most parents will be willing to do.

Any thoughts on if this is even possible using existing modules? This project is a volunteer project and I don't mind investing my time to set it up, but I don't have the resources to create a new module or highly modify an existing module if this can't be achieved 'out of the box'.

Thanks in advance for any input :)