I'd say the only way you could truly make a difference is to focus on what method works best for you. If others spend double the amount of time on one thing they will be better than you at that one thing, but (now speaking from personal experience) you will reach a point where your work will be of great enough level where it would be smarter to broaden your skill palette in other areas. You will improve greatly in things like writing and programming as opposed to getting a little bit better at art. So investing your time in that could be a smart thing to do. It's ok to learn a different set of skills, as long as each of the things you learn can also be ushered to become part a whole. That's a condition for me personally. I agree with you that learning about one thing also expands knowledge in other areas.
We live in an age where anyone can learn anything and starting a business is easier than ever before. Which means that you need to become a powerhouse, not just because you want it but also because it's the only way to actually do something nobody's done before. The word unique has lost all it's meaning for me, but truly unique concepts are a fusion of several vastly different elements. The factor that makes it work is the competence of the people involved.
As to your third point. I'm both self-taught and college educated in two very different things, but they are two sides of the same coin. It's just that, nobody's attempted to put a coin like that together (yet). I've still got plenty to learn before I actually put all my money on it. I could go on, but talking is easy and I prefer talking after having done something first. I think as long as you're dedicated you can make it work.
Emrox
I know they changed it years ago but I still like doing that thing where you have just the one image at the end of your post