Omega
Vindictive Courier
I use roll to switch to enemies quickly, slit that guys throat then that one, then that one. It's like an Assasin's Creed combo, also helps me get away from an area I just shot an arrow from which didn't kill the enemy. As for shadow warrior, that's pretty good, gets you out of tight situations fast, as Red said if you used it fast enough you can perform a sneak attack. Shadow warrior + shrouded gloves you can pretty much kill anything apart from dragons in one hit. I guess it all depends whether you're going to be using sneak most of the time for taking out threats, if so put all the perks in if not, don't.
