I like the concept of following members. It's not a feature that I use a lot, but I find it useful on some boards. It is also interesting to see the forum members who are following you. I think it is a useful feature, not just because it allows you to keep up with members with opinions you value, but because it allows you to check on the forum opinion about your posting behaviour.
That would be most, and probably, only useful to traders or following theymos and other mods in case there's some ANN. Other than that, I don't see any practical use for the rest.
but because it allows you to check on the forum opinion about your posting behaviour
Merit?
I'm kind of neutral, there's no reason for that option to be implemented but it would be a small feature that would be nice to have.