Firstly, that guy recommending CPR - it's painfully obvious that he knows less about trauma first aid than I know about interpretive dance.
I suppose there are worse things than CPR you could do to a gunshot victim, like you could shoot them again, or maybe stab them...
Any of this type of measure (first aid training, encouraging people to arm themselves, etc.) isn't even thinking about addressing the problem though - car insurance doesn't stop your car being stolen.
Neither do the protective measures like bulletproof glass or secure entry - I mean, in a fire situation everything would open for efficient evacuation and everyone would go outside right? So just set off a fire alarm and wait somewhere outside the fire escape with your gun...
So, the next option is gun control...
I don't believe that will work.
Look at how strict gun control is in the UK, people still get shot. Enough that there are dedicated armed response police. If 'our' model of control worked fully, we wouldn't need those, a stick and a whistle would be plenty.
It's either uninvent guns (erm...) or control them to such a degree that they might as well not exist. Even then, it's only restricting the tooling.
Neither of those are viable either.
What needs looking at is why these shooters go on a shooting rampage in the first place. Why does society breed that mindset? What is it that makes these people think it's a good plan to go kill a load of other people?
That's the real problem that (apparently) nobody will admit to - and because it's not admitted it can't be addressed.
From the amount of reports, it's hardly justifiable to say it's just the occasional nutjob.