I, too, have wondered if Disk Warrior is not as useful as before, considering the stability improvements in OS's after Snowy. FWIW, in running DW and Disk Utility, DW found some minor issues that DU didn't, but it probably didn't matter. The best thing about the DW upgrade is that you can create a recovery partition on the DW thumb drive and boot from that to run DW or any of the Apple utilities found on Apple's recovery partition. As an added bonus, booting from the thumb drive is super fast compared to booting from a CD.
IMHO, I wouldn't disable SIP. That's like walking the tightrope without a safety net. As far as Gatekeeper is concerned, you should familiarize yourself with
OS X: About Gatekeeper. That will allow you to keep SIP enabled and bypass Gatekeeper when necessary.
BTW, I agree with your assessment of Snowy. That was a great OS.
