Hi Robert,
Hope you're enjoying CaseComplete and find it useful.
In answer to your first question: While not directly supported, there are several ways you could define interface requirements:
1 - Use the glossary. For example, you might want to create an entry called "customer data" and define it as specific as you need, such as, consists of First Name (20 characters), Last Name (30 characters), address1, address2, etc. Then when you type "customer data" in your use case steps CaseComplete will automatically create a hyperlink to it.
2 - Create a UI mockup by creating a diagram. Note diagrams can be owned by any package, actor, use case or requirement. You can see an example of a mockup of the CaseComplete website being edited in CaseComplete here:
http://www.casecomplete.com/Images/ccmockup.png
3 - Create requirements and attach them to the appropriate use case(s). Attach them either via drag/drop between the main list and the model browser, or via the details tab a of use case. Note that the "Type" field for requirements is customizable via Tools/Predefined fields. So you could create a new requirement type called Interface if you wanted.
Regarding your 2nd question, there aren't immediate plans to support IEEE 830, but I'll add it to our feature requests database for consideration in a future release. CaseComplete Word reports are easy to customize, so you might want to try it yourself. Please see Custom Word Reports user's guide available from the help menu. If you give it a try, let me know how it goes.
Doug
Serlio Software