No offence taken, Tom. Au contraire'---I appreciate your knowledge! That fact about Bloomfield is interesting, isn't it? I read an interview with Mike wherein he described arriving at the session intending to play guitar, but upon hearing Robertson, move to piano without being asked to. They both played in a similar blues style, and were two of the first white 60's guitarist to get good tone (though they played very different sounding guitars---Bloomfield a Gibson Les Paul, Robertson a Fender Telecaster), before most of the British players got hip, one exception being John Mayall's guitarists, Clapton and Peter Green. In '66 Jimmy Page, when taking over as lead guitarist (from Beck) in The Yardbirds, was still playing a Telecaster, and had horrid, thin tone. As did Keith Richards.
Musicians/singers/songwriters getting screwed financially is a very old, common occurrence. Chuck Berry was one of the few original Rock n' Rollers to possess business acumen, most others being very naïve and overly-trusting, even The Beatles (whose terrible songwriting publishing deal robbed them of many millions of dollars. Brain Epstein did NOT know what he was doing). In the early 2000's, Emitt Rhodes actually had to move into his studio (a huge converted garage located behind his house in Hawthorne California), and rent out the house to pay the mortgage.