What is linearity with frequency like? I guess the sensor has a roll off at some frequency due to its mechanical characteristics?
The block diagram suggests no analogue filter between the mux and A/D. How does the system deal in practice with vibration frequencies above the Nyquist rate? What would happen in practice to vibration energy at 400 Hz, or 800 Hz?
How does the accelerometer respond in practice to an overload acceleration? Some accelerometers simply limit, soft or hard, which is ok, some do some very odd artefactual things
the frequency band is determined by the output ODR: ODR max is 1000Hz, so maximum detectable frequency is 500Hz. The frequency response before this limit is flat.
The risk is to have an aliasing effect. The aliasing filter is not selectable from memory, but there should be an embedded anti-alias filter inside to prevent this effect.
an overload acceleration will saturate the output, giving maximum the selected full scale