Sorry to bring up a month old post, but I work for a Cadillac dealer and have plenty of experience onstar...usually when its not working correctly.
As far as I know, they don't track your speed. That info is recorded in the SDM (sensing and diagnostic module..or air bag module) and can be accessed after a crash; but not by the dealer. That stuff is access by some outside agency. It will recorded MPH, brake appication (how hard the break was applied in some models), acclerations (from the g-meter in the SDM) wheel speeds......ect leading up to the impact and whay deployment loops where popped off. The VCIM (vehicle communications interface module or "onstar module") is sent a serial command to contact Onstar when the deploys an inflatable restriant or when an accident is expected (based on the g-meter). We had a sky customer get a call from the Onstar after some intential aggressive manuevers because the yall rate was too high
As far the key locked in...I also do roadside assistance for Cadillac. For the caddies, as long as the car is covered in the 5y/100k miles, that roadside service to retrieve keys is no charge to the customer...yeah, it might take longer then having the satellites unlock the car, but it doesn't cost anything (althought tips are appreicated

). I can't comment on the service for other GM vehicle as I only deal with Cadillac for roadside calls.