Document Center and other sites

Question

I've been given a project to complete. There will be four web applications which communicate with an EDRMS - initially entirely in SharePoint but later the EDRMS will be extended with a third party solution.

1. Web App 1 - read only access to all final version documents
2. Web App 2 - Department based collaboration
3. Web App 3 - Team based collaboration
4. Web App 4 - My sites

How do I get them all working with the EDRMS in SharePoint without causing too many hurdles for the users to jump over.

Do I configure Web App 2, and 3 to publish Major versions of documents to the EDRMS? if so, then how do I then show on a users My site which documents they have been working on? and how do I link to them from Web App 1 - is it all just manual?

The main issue is that users seem to think that it all just magically allows access to documents in the EDRMS - whereas all I can seem to find is

1. Records Centers are for archived documents which are not going to change (or not often)
2. Document Centers are for live documents to be edited on but mean that I cant use a Team Site as such as users would edit documents in the Document Center instead of a Team Site
3. Once a document is published to the Records/Document center its disconnected from the original source of the document - ensuring that users look at te Record/Document center version is managed by business process

ANY guidance would be appreciated!