Yes, I do put the loops in the loops folder (I find this process to be very clunky, but if it works I would be happy with it).
I assume, and this my a big assumption perhaps on my part, that because the loops are Acidized and BB knows the root and original tempo of the sample, that the loop will follow the chord sequence defined in the song.

This would seem to be the behaviour of the installed loops in this folder. But I feel sure that BB doesn't actually work on the root and tempo of a non BB ACID loops, because that would seem to be my problem. I am currently in the process of trying a few things out along those lines but was hoping to short circuit the the task if I got some pointers. My guessing is that the parameters need to be set for the loop in RB regardless of whether it is an ACID loop or not. Also guessing that any old loop will work so long as I can tell RB the original root and tempo. But we'll see. Time is my problem.