Serious question, how much NHL hockey did you watch before the rule? It really wasn't the way you might immagine it was.
And I do not think that removing the instigator rule is all that is needed to stop cheapshots - it is one step of many that should be taken.
Penalize blindside hits, remove the instigator, outlaw hard pads, get serious about suspending offenders. That would be a good start.
In the event that there would come a time that league thugs started forcing Dats and those like him into fights, I would want to see that addressed. I don't think it would become an issue, as it wasn't an issue before.
I would say that the other changes you suggest, beyond the insitgator, would be enough. (Well, I'd also mandate proper chin straps on helmets, and probably look for improvements to visors. Hard pads need some analysis. The pads themselves aren't a problem, but they probably contribute indirectly to more reckless play.)
Now on to the instigator rule. Serious question for you. Do you really believe that the chance (not even a guarantee) of getting a minor penalty is keeping enforcers from preventing cheap shots?
First of all, the instigator rule does not prevent violent retaliation; it only assesses a penalty for it. Now think about it logically.
You have a 'cheap-shotter', under current rules, if he delivers a cheap shot (like the Cooke hit), he faces the possible consequences of: Penalty in game (minor, major, misconduct, ejection...up to the discretion of the refs), League Discipline (suspension, fines), Retaliation from the opposing team. So cheap-shotter must either ignore or at least not be thinking about any of those consequences before taking a cheap shot.
You have an enforcer, under current rules, he may (probably even) get a minor penalty for retaliating and a misconduct. Frequent offenders (or in certain circumstances) may face more serious discipline. To NOT retaliate, he must consider the value of his 'enforcement' to be less than what would be lost by taking the penalty. This alone suggests that the 'deterrence factor' of enforcers can not be very high (at least in the minds of the enforcers themselves).
Furthermore, removing the instigator rule would NOT allow an enforcer to force someone into a fight. All Cheap-shotter has to do is ignore the enforcer. How many enforcers are going to chase someone down from behind and risk a Bertuzzi-Moore incident. (Oddly enough, people often cite that case when arguing against the instigator rule. As if removing the instigator would make it impossible to turn your back and skate away from someone.) The league would never allow someone to just pummel another player who wasn't defending themselves. There would be legal ramifications. So at best it allows maybe one or two shots that maybe (not even guarantee) doesn't result in a penalty on the 'instigator'. Consequently, it would also allow the same for bullies to do the same to star players / non-fighters (even if such a thing would be rare [as an aside, I'd suggest you look into the old Flyers borad street bullies]) Also note that the NHL has had at least some version of the instigator rule since the Original 6 days. And really, most of the criticism of the instigator rule would more properly be directed at the Agressor rule, which is the one that penalizes players for fighting unwilling or defenseless opponents.
So you trade increased risk (even if only slightly) to star players for an increase in the likelihood of one potential consequence (the value of which has already been determined to be less than a minor penalty) for the cheap-shotter.
You seem to have this romanticized, WWE-esque notion of enforcers as some kind of super hero, before whom the forces of evil cower in fear. Or rather, they would be, if not hamstrung by the instigator rule. As though they have the ability to protect others from harm, but are too honorable to break the rules in order to do so. As if having a just cause would instill them with some righteous power to conquer their enemies. Like said enemies would, if the instigator were removed, be unbreakably bound by some code to accept their due punishment.
The truth is, players can't police themselves. Like I said before, all that does is allow the toughest guy around to make the rules, even if that guy happens to be one of the 'bad-guys'. Discipline has to come from authority. Authority can not come from violence. It's too inconsistent.