Shagbark is what we have around here, and makes a pretty nice bow!
As far as set... poppy cock! I keep them nice and dry in the hotbox and no-set tiller them. Even without tempering they wind up with usually 1" of set or less in a regular design, and so far I've yet to make one that has more than 1" of string follow.
Like any other wood, and animals and people and what not, you have good and bad pieces. The bad pieces just make lighter bows, the good pieces make heavy-weight rocket launchers
As for the bark, a sharp drawknife and twenty minutes will get me down to the soft inner bark. When I throw it in the hot box to dry it uually all dries up and peels off. Piece of cake, and leaves some cabmium for camo.