I have been pestering Lori Maloof for SDATA docs regularly since the Atlanta Customer Symposium in January and have not yet gotten past ""We'll have it at Summit."" There are sessions scheduled at Summit, for 100 & 300.
As for the security tab, I believe it is like the ODBC tab except it controls SDATA access instead of ODBC access. However, I could be attributing logic to Sage development efforts that is not in fact there...