That sounds like a very interesting DSC you are writing. Please also be aware that we have a JDBC service in the Foundation category. You may be able to just use it rather than writing your own.
You asked: "Question: How do I access native oracle/transactions/jdbc/db layer/etc?" I think that you probobly need to import the pakages that you need to call. There is an example component.xml here
Glad to hear that you got the Plug In installed. We'll be uploading a "lighter" one soon that's easier to install with fewer dependencies. Watch out for that.