This build works really well. Killed Baal as fresh 120 with only 1 death - even that was only because it was so long since I fought Baal I forgot how fast-hitting those little dinosaurs are that he spawns. That was in mostly leather honorific gear as well, so not bad at all.
I stopped trying to hide behind a merc - if I take one now it would be A1 zon. Relying on the sin's speed and 3s Blink makes it easier and more fun.
At 121 I'm using more regen gear like akbugger described, when I get a lot more damage I'll try the other way, but for now being able to spam PS and heal in a fight seems... kinda important.
EDIT: Getting the hit recovery breakpoint bapja highlighted is important - it makes a big difference that you can actually do something when they get in your face.