Same here 
The menu option will ask for the IS repository database account, where you store the data for IS. This would be IS_REPO or some variant and could be in Oracle, SQL, HANA, etc. If you log into the CMC and go to Applications > IS Application > Configure Repository, it will outline the repository details. This is what it wants ALL IS users to have, which would allow any user with SQL Developer/ TOAD/ etc to access the repository, unless you put database controls over users to prevent login to the database.
There are lineage and impact reports that actually contain some useful information, albeit SAP have made it hard to access or customise, unless you know Crystal and want to change them each time you upgrade. The IS User Guide outlines what's in the reports. In the 4.2 SP7 version of the user guide, this is in section 3.1.9 on page 400.