I beat Dishonored using stealth almost entirely, only making kills on a few occasions and I have to say it was a pretty damn fun game. I remember Niki mentioning that he wishes there was more variety for knocking enmies out and I while I do somewhat agree, I found that the variety in stealth is more about enviornmental exploration than anything. To be totally honest I only used 1 sleeping dart the entire game, I never fired a regular crossbow bolt or a pistol or anything. I only choked guards out on occasion but even then I generally just sneaked past everyone I could to avoid their bodies being found end-level and thus increasing my chaos rating (assuming that is effected which I assumed it was). The problem was that yeah, I basically missed out on all of the weaponry and half of my powers by going pure non-lethal stealth. Still it was very fun regardless.
So after beating it with only a few kills and almost never alerting anyone, I started a new save file where instead of knocking guards out I simply kill anyone in my way. I don't go out of my way to kill everyone or anything like that since I still see it as a stealth game, but if someone gets in the way I don't take the time to wait it out. I simply deal with them and if I happen to get spotted I unleash the full force of Corvo's power and fuck everyone up that made the mistake of coming after me. I have to say that even by the third mission the game is quite a bit harder, and the enemy layout is very different than my first playthrough. Even though I'm only killing a certain percentage of the enemies there are a hell of a lot more Weepers, and rats around, not to mention more guards and even assassins coming after me. It is pretty satisfying to finally utilize all the weapons and powers at my disposal. With so many ways to complete each level I think Dishonored almost demands 2 playthroughs to get the full experience.