Hi,
I have implemented a similar case whereby we did integrate with a TSQL by using the DatabaseConnector module, whereby we had creatd a service account with extended rights so all users could do their stuff.
The reason we had created a super service account was that our accounts are authenticated against Active directory and we don't store passwords in Mendix systems. So we could not use the AD accounts through the databaseconnector.
However if you do store (which I don't expect) credentials you could use that in a secure way with the database connector without having a generic super user account.