Hi again,
Yes, DBXL is just a Web Service, so you can submit to it without having to store it in a form library. To reopen a form saved to DBXL, you will want to configure a data view on the database where you submitted it. There are various ways to do this and they are all documented on this site. Please let us know if you can't find the documents. We are also working on XTPs to make it easier for form developers to add this functionality to their forms. Send email to Support at Qdabra dot com if you want to get this XTP when it is released.
We don't have an easy way to automate removal of documents. There is a web method RemoveDocument that could be used. If you would like us to create a tool for you, we could probably do so for the cost of one support incident. Otherwise, we will add it to our feature list moving forward and try to get to it later this year.
Hope this helps. Let us know if we can be of further assistance.