I have a much more specific suggestion that would've vastly improved Dishonored, specifically for stealth runs. Forcing the sword/dagger into Corvo's right hand was bloody stupid design choice. It's a lethal weapon with NO place in a stealth playthru. As such, playing a low chaos run you only have the left hand for crossbow, spells, etc. It should've been like BioShock/Skyrim in the sense that anything could've gone in either hand.Dishonored: This one may go over the 'too broad' line, but make low chaos runs more fun. Now, I get the idea that it's called 'the high road' because it's generally harder to be noble and altruistic than it is to be petty and vengeful, and I respect trying to incorporate that into the gameplay experience, but Dishonored takes it to the point of making low chaos runs downright tedious,
Also, the pistol...it's pointless. There's no need for a second ranged weapon when corvo has a pistol crossbow. My improvements to the game would be to remove the pistol outright, have either hand able to hold any item (eg. crossbow with sleep/lethal bolt in one hand, blink in the other) and perhaps another spell or two geared toward stealth. Perhaps Throw Voice as you suggest, would be a brilliant addition to a stealthy repertoire, or a similar "distraction" mechanic to enable breaking guard patrol patterns temporarily.
One other thing which I think is a missed trick, is making Blink a little offensive, Nightcrawler style. Why couldn't we Blink/BAMF a *conscious* guard and drop him from a height/into water/etc? Would've been fantastic!
TBH, Dishonored was a stealth game that allowed it to be played "loud" in order to please more people. Thief/Hitman (the actual, good games, not the reboot/Absolution crap) could only be played stealth. Dishonored stealth is harder than "loud" and takes significantly longer as Corvo hides patiently but IMO is the way the game is intended to be played. It can be done loud and over in a handful of hours and the tragedy is that the majority of the magic abilities cater to this playstyle in what should have been primarily a stealth game. Perhaps it's the result of trying to please the masses/broaden mass-market appeal.