Can I do this with FrameMaker ExtendScripting?

Using FM 12.0

I'm a coder so coding is not the issue here. It's just my lack of familiarity with FM ExtendScript and the art of the possible.

I want to create a script that

1. Inserts a marker of a custom type called Editorial Changes. We can safely assume that this marker type (Editorial Changes) exists already.
2. Displays an advanced marker window: Please see the mock-up window below. Studying sample scripts such as SnpCreateCheckBoxRadioButtons.jsx, I know I can create something like that window, so that's not an issue.
3. Once the user has finished filling the fields, I want to capture the data and store it inside the marker field, say as an XML snippet.
4. Later on, when a user selects a created marker of type "Editorial Changes," I want my script to intercept that event, grab the XML content from the marker and display my custom window with all these fields.

Does the sequence outlined through steps 1-4 doable via an ExtendScript? If you've done something like that and have a script lying around, would you mind sharing?

Thanks!