You appear to have two issues -- granting unnecessary privileges to SDE and using the SDE user for unnecessary purposes. The SDE user exists to manage the geodatabase install. It should not own user tables, and it should not be used to access user tables. The password for the SDE user should be tightly controlled and rarely used. -V
Yes I am granting too much privilege "SDE" because there is an application that uses SDE to access data. Pardon me..
So what are the implications of changing (adding) the Server Roles for SDE, from Public to SYSADMIN + Public ? Why cant I edit a FC after changing it ? I have reports from users that they cant edit FC anymore.They also cant update attribute tables.