First of all, let's make one thing clear - I want the sport to be as safe as possible, but I disagree with the path some of the discussion is taking.
After having some initial doubts, I'm ok with moving the Kick-off line to the 35. But sometimes, it sounds like the only way to prevent dangerous play is to add more and more rule changes. In the same way you can improve car and driver safety, there will always be the risk of serious injuries and fatalities in IndyCar and Nascar (well, until someone puts drivers in a VR simulator and control their cars via radio). What the NFL must do is to take out what are the avoidable variables without affecting the quality of play - keeping with motor sports, in Formula One, Turbo-charged cars were outlawed because they were a fire hazard in case of an accident (Paletti and de Angelis died of burns or smoke inhalation). 5 years after being outlawed, Senna and Ratzenberger died due to collisions, and while the safety of the cars was much improved, they also gimped race courses so much races are now decided by qualifying, first turn and pit strategy, and not so much the quality of the drivers overtaking. Like myself, many fans stopped following the sport after races became a slot-track with just one track for all cars.
Players until very recently were not fully aware of the risks, but since it's all becoming right in the open, they should also evolve their game to something more aware of what might happen in 20 years after retirement, moving away from the macho "If they gave me a helmet, I'll use it" BS. If players lack self-preservation, no sane amount of rule changes will be enough - going back to the auto sports comparison, if Nascar drivers though they were just doing a real version of good ole' Demolition Derby, how much would life-impairing injuries and fatalities increase? Instead of that, we see the Players Association seemingly being apologetic towards Saints players, who willingly took part in actions to deliberately injure opposing players. Plus, NCAA should be also doing something about that, although it's unlikely since admitting health hazards would also put them in a place where they'd also be liable for future health conditions, and heavens forbid, NCAA paying anything to an athlete.Early on, kids are being taught to lead with shoulders and helmets, not wrap around with the arms. There's a reason helmets and padding don't have spikes on them and gloves don't include built-in knuckle dusters - they're protective gear, not a offensive weapon. I doubt many players in the NFL are able to do an effective wrap tackle, but boy, do they know how to launch themselves at someone else.
I understand it's easier to say "you can't do that, and if you will, you'll get get fined and suspended", but in the end, the decision to go head first into someone's head is on the players. Self preservation should be the first line of player safety, regulations only exist because sometimes in the heat of the moment the lines get blurry. If more and more regulations are needed, then the problem aren't the rules.