[flexcoders] Making system calls from flash

I know that a Flex application once it runs in the flash player, is bound to a security sandbox. This means restricted access to local resources. But suppose I wanted to call systemfunctions (e.g. manipulating a display device) from flash: can it be done? how?

[flexcoders] Accurate timing with flash

How accurately can operations be scheduled in Flash. For example, I want to be able to perform a particular operation on a number of separate, unconnected clients on exactly the same moment(e.g. they should start blinking a piece of info at exactly the same moment with the same blinking