I think that is the same thing as the taint.
Personally, I think it's more that Molly keeps looking to magic to solve problems.
I don't think so. With the taint removed, if you explained to them that doing that did more harm than good, if their real motivation was to do good then they wouldn't do it any more.*
But even if not, a clever Blackstaff could get around that... You wouldn't have to attack their motivations at all, just make them not think of using magic in that particular way (exactly like what Mab did to Harry).
Well, both of these rely on each other, so first I'll point out that what Mab did to Harry was stupid, dangerous, and necessary. When Harry realized what had been done to him, he had a total freaking meltdown in Michael's shed. He literally did not understand the words "blasting rod."
That was after a day. Imagine what it would do to a person if it came apart after a month, or a year—suddenly realizing that you were not who you thought you were for an extended time. I think you'd have some fundamentally fractured psyches.
As far as the first, I disagree. I think you'll get some who will understand the damage they're doing, but there will be others who will see a problem that is too difficult to solve without magic, and they'll fall back on it, even if their intentions are good. I honestly think that the only way to make sure they don't do it again is if they set aside their magic, which brings me to my next point:
Well, it seems to have worked for Harry... the Winter Mantle temptations have nothing to do with black-magic corruption. He really hasn't shown any signs of that since he got rid of Lasciel's coin, arguably not since well before that (all the anger stuff in PG-WN might have been pure Lasciel influence; I'm not sure anything since GP is confidently attributable to black-magic effects).
Yeah, I know it's the Winter Mantle. I don't think Harry was ever tainted to begin with. I just think that he spent his childhood getting pushed around, then his teenage years getting abused, until he finally was strong enough to stand up for himself. Occasionally, he feels like using that strength to curbstomp his enemies. That's entirely normal; I get that feeling on occasion too.
But Molly certainly IS tainted.
Also, every time Molly uses mind magic after PG it seems pretty justifiable, even if technically against the Council's laws (confirming manipulation on Harry in SmF and Luccio in TC*), and Harry was willing in Changes so I don't think that even counts as against the Laws.
Yeah, and she's been entirely stable since Changes, right? What about all of the murders she committed as the Rag Lady? She has a meltdown explaining how easy it is to kill crooked cops with magic, and it's pretty obvious she's messed up, and not just from screwing with Harry's head.
I don't particularly care about the Laws, as I think that they're unnecessarily byzantine, but there really is no way to reform warlocks after a certain point, regardless of their motives. I mean, Molly was protecting Chicago, but still outright killing people with her magic, even though there were A) other options available, and B) she knew it would screw her up further.