[Q] Just want to use the "Titanium Backup" app

I am using Stock Kernel and CM 12.1 on my Oneplus One. I just want to use the "Titanium Backup" app that need to run on Root device. What exactly I need to do with my phone: ???
Just Unlock my Bootloader and run SuperSU ?
Can I still go on and use Rom OTA after I Unlock my Bootloader ? :confused:
Thanks!