Both are fine. The second is a little more formal and 'educated, in tone. There's nothing 'arcahic' about this sort of construction. Repitition of this sort has a name but I can't think of it just now.

Yes, both are fine. I disagree with Michael, I think removing the first 'of' sounds even less natural. Both of your sentences are scholarly (good for an essay, not so good for common speech). To make it more natural in a conversation, I think I would change the whole structure. Example: "He talks about how it's important to make good decisions and control your life."

"He tells the importance of making good decisions and controlling one's life" In this case, if you use "of" too much, it makes it sound archaic and less natural.