Can you write usage examples to illustrate the difference between "about", "regarding", "as for" and "as far as... is concerned"?

I'm not feeling particularly confident about this answer, and I figured I should say that from the get-go. These words' usage is very nuanced and I know I'm going to leave something off — likely lots of somethings. So this could be either brilliant or a train wreck, and most probably the latter. Take it with a grain of salt. Okie dokie. Here we go. About is mostly synonymous regarding, except that the latter is somewhat old-fashioned and you're more likely to hear about in speech. (At least among my crowd in California, whatever that's worth.) As for… is used as a connector. It means that you're turning away from addressing your former subject and on to something else. As for your comment regarding XYZ, ABC. As far as … is concerned can be used much the same way as as for…, but it has an additional use: if you put a name or a pronoun in there, it means that you're about to state that person's opinion or the kind of situation I use in example #2, which I'm not sure how to describe with words. (EDIT: Lana Fisher has suggested that this describes the state of mind of another individual as seen from their perspective.) As far as I am concerned, it's a bad idea. As far as Elizabeth is concerned, we were never here.