Grey 1 - The bands measure the SD from the MA. The MA isn't stationary, so I don't quite grasp what you mean by the first point.
I find the bands useful in describing price action relative to itself e.g. the squeeze, expansion, relative high low definitions etc.
Sure volume isn't included, and I agree that price is manipulated a lot more than most would like to believe. Thats why volume should be taken into consideration when making calls.
They are not perfect either - but what is?
To be honest, I'm not the biggest fan of TA anyway! (indicators, chart patterns such as triangles H&S etc)
I don't think that B Bands should be used on their own as entry signals, but they are very descriptive of price action when taken into consideration with other variables?
Wouldn't you agree??