Output Data Rate for this gyroscope is way lower than the clock rate?
The "Output Data Rate" is not the bit rate of the interface, but rather the rate at which it samples the values being measured. If you set the Output Data Rate to 800 Hz, you will read out a packet of data every 1.25 ms using a SPI data rate of 10 MHz.

The cutoff frequency for the low-pass (antialias) filter associated with the sampling process is tied to the Output Data Rate.