Don't know about the clock, but the SRS system is what controls your air bags. It is usually indicative of the system having an error and it will not likely work correctly if you are in an accident. I recommend having that checked out post haste.

Seatbelt problem: did something fall into the seatbelt female end? Might try taking that piece out of the car and shaking it out... something to consider.

The rattle could be anything. You have to locate it... there's no way someone that hasn't been in your car will be able to tell you where that problem is...

hih