If you are working with admin privileges/authorization, you should know exactly what you are doing (and also document it).
It seems to me that you are missing a good setup for database administration tasks with the proper management of authorizations/privileges. So you should use some other user with SYSCTRL, SYSMAINT or whatever privileges you need for a specific task and no other, higher privileged user.
Also, activating NLI for a table doesn't change anything of you have auto-commit activated and/or if you don't change data in the transaction where NLI is active. If you had auto-commit (the default), then the data loss has a different reason.