fijdor.....Next time you hover the aircraft with nothing hanging under it.....establish a stable hover into wind.....then start wiggling the tail using the Tail rotor pedals....gradually work them with increasing amounts of input and watch the aircraft begin to roll a bit. The high tail fin position of the Tail Rotor on the 205 provides for that kind of pedaling to cause the aircraft to react in "Roll" as well as Yaw.
A lot of the symptoms you mention are classic Bell LTE.
I wonder if you might be experiencing LTE right at the airspeed where you begin to experience the onset of RBS. As you are right up there at the very top of the charts.....you are operating in a region of flight not all that many folks do.