There are a few fence sitters I tend to talk to, most are conflicted, I think two or three lean towards the left.
I try to look at these kinds of legislation from their side as well, it can be difficult but I think it heals broaden the scope and helps you find flaws in their arguments.
It's as you said, you can know all the rules in the book, but a lapse in judgement or case where you just go through the motions to get certified doesn't necessarily guarantee that people will be safe.
People do stupid things, some more than others, and there really isn't a thing you can do about it. Each and every one of us has to make a decision, it's just that there are those the choose poorly on what they decide to do.
Legislating what you need or do not need to know is just as futile as trying to legislate morality. You simply can't, due to something that is commonly known as free will. I understand where they're coming from though, they want to do something, you want to try and make things safer, but the sad truth is, more often than not, there is nothing you can do.
Also I feel it is my responsibility as a law abiding gun owner to educate those who are willing to listen, and present our arguments as calmly and intellectually as possible.
Our image isn't exactly stellar, with characters like Alex Jones "representing" us in the media, we need every responsible firearms owner out there pulling their weight, educating others as well as themselves and presenting to the public what we really are all about without the rantings and ravings of a hyper passionate conspiracy theorist that just happens to be a Pro 2A advocate as well (I know several people like Mr. Jones as well, and they drive me nuts)