If you create and save content to your Modified Items list, if you select either the XMl or any one of the generated assets, you can do a Submit or Undo, and we automatically promote that other related items or undo them as well. We can do this because we should the delta between the current view of Staging and your sandbox, and can run through that constrained list, look at each asset and find its corresponding source and package up.
Now, delete is a bit of a different case. In the case of delete, we can't run through a quick list of mods and match generated items to source and other generated items. The only efficient way to do that is via Search.
AVM store indexing and a corresponding API for search was new to 2.1.0C (and now, in 2.2.0E, a GUI for simple search in a user or Staging sandbox/store). This meant we weren't able to leverage for delete in 2.0.0 and 2.0.1. Unfortunately, we also have updated delete for enabling this specific behavior on XML assets generated via a Web Form (and specifically those that generate renditions). This should be added as a feature improvement in our JIRA.
Now, one thing you can do: add a custom action to implement the correct delete behavior leveraging Web Scripts. Our dev plan is currently locked through our 3.0 Community release, but there's no reason that you can't add this custom behavior today.
Kevin
