Samsung Galaxy S accelerometer details
All of those details are heavily dependent on the firmware setting up the chip, low level software (Android OS) massaging and delivering the sensor data, and finally the application-level software further massaging and delivering data. At the firmware level, it would be useful to get an SPI/I2C sniffer, like the Bus Pirate or Open Bench Logic Sniffer. I wouldn't be surprised if applications were able to access this level, as well. In other words, the initial or default state may change. It will be very difficult to attach probes, however.

The Android OS is largely open-source. Check it out and see if you can find the relevant blocks of code and libraries. It would at least set the initial state, and likely define an API to change it.

The wrong way to go about this is physical tests while taking measurements with an on-board application. There are at least 3 layers of algorithms fiddling with the sensor data.

You cannot determine drift from the datasheet. It is dependent on temperature, age, and batch/wafer.