The one thing he is innocent of is causing Kathryn's accident. Kathryn had decided to go to Boston. Bad things happen to people who leave Storybrooke. Gold took advantage of the accident, but he didn't directly cause it. Yes, if you take it back to the fact that he made the curse, he was responsible for bad things happening to people who try to leave, but he made no direct move against Kathryn.
I'm perfectly willing to take it back to the fact that he created the curse. It doesn't matter to me how long ago it was or whether he specifically had Kathryn in mind - he willingly and knowingly created the no-exit situation. If I dig a big hole in a place where people are known to walk, then make sure there's no blockade or warning signs around it, and then wander off to do my own thing, any injuries to anyone who falls into that hole are on my hands, and that is pretty much what the exit from Storybrooke is like. Plus, in order to be prepared to kidnap her, he had to know she was heading that way and he did not stop her, so that's plenty directly involved to me. I also think he set up the whole law school scam. No way she could have actually gotten into a Boston law school. He's been long-conning for hundreds of years; a fake acceptance letter to set up the accident and kidnapping are much more believable to me than the idea that Kathryn actually applied and was admitted to a real law school.
But Emma did say he managed to not damage anything he needs, so even in his fury, Gold showed some restraint.
I would chalk the lack of mortal injury up to the fact that Gold is a scrawny old dude and Moe is pretty solidly built, not to some deep reservoir of restraint on Gold's part. I think he would have killed him had Emma not shown up, so not killing him was Emma's choice, not Gold's. Granted, if she had taken note of the fact that Gold all but TOLD her straight out that he planned to do just that, the entire situation could have been avoided. Maybe that's why he wanted her to be sheriff - he knew she would suck at it.
But in the time we have seen him he has tried to connect David with Emma's mobile, gotten Mary Margarette off on murder charges, manipulated things so Emma became sheriff and not killed anyone.
I don't see how any of these are actions that speak well to Gold's character or nature. Any connection he was trying to make for David was for Gold's own purposes, and had he really wanted to make that connection, he would have done more than point out the mobile. As far as getting Mary Margaret off on a murder charge - he's the one who set her up on those murder charges
. That ENTIRE thing was HIS plan from the start. I cannot see how he can get any credit for getting her out of a situation that he masterminded, initiated and executed. Manipulating Emma and the election and setting a building with people in it on fire so that he could have a sheriff who owes him favors are also not behaviors I consider signs of a person on the path to anything approaching redemption. I consider his lack of a murder count to be strictly due to 1)Emma stopping him from killing Moe,2) Emma rescuing Regina and herself from the building he set on fire with them in it, and 3)the fact that he just hasn't really needed to kill anyone to suit his purposes yet. When it comes to that, I doubt he'll hesitate one bit.
The way I look at it, there's a fairly simple and clear way to deduce who Rumpel really is underneath the curse. The power the curse gives has an observable, physical effect on the cursee. That power literally
corrupts the cursee's body. So I look at how corroded Rumpel was already getting immediately after it took effect (when he comes back into the village), and I look at how thoroughly gone he physically was by the time of dropping his son down a vortex, probably only a few months later, and then I compare that to how Zoso looked after having been under the curse for a much, much longer period of time. Zoso looked a little crappy, but not too bad all things considered, so it must be possible to resist the corrupting nature of power to some degree. The way I see it, if Rumpel's decay was so much more extreme, it's because he was already, at his core, a very weak and corruptable person.