Barbara Sher

Thanks to Merlin for recommending Barbara Sher and her philosophy of "scanners": people who have (or rather, are told they have) too diverse interests for their own good. It is awesome.
Turns out I actually own one of her earliest books, Wishcraft. It is not quite the same, but this one is available free on the web.

This blog is a good example of a "scanner's" (me) activity: I don't earn money from it, but it lets me use many different interests at once: writing, photography, drawing, talking about films, books, and philosophy...
I am not entirely convinced that scanners are exactly the type of person I was trying to define, but there certainly is at least a huge overlap.