I tie many, many patterns with turkey biot bodies. Even my Adams' are tied with gray turkey biots for bodies. In response to your questions:
1. I do not soak them in water prior to tying. They are far less brittle than quill stems, which do require being soaked in water.
2. I do not coat the bodies with any cements/liquids. They are quite durable just tied on and wrapped. In fact, I've never had one break and become unwrapped.
3. I would say floatation is fairly close to the same. If anything they may float a little longer since they don't become water-logged, but they difference is negligible. I do think it makes a more life-like body than a dubbing body however. I've had fish refuse a dubbed body BWO and take the same pattern tied with a biot body.
Hope this helps,
-Darryl
My one wish is that when I die my wife doesn't sell my fishing stuff for what I told her I paid for it...