Yeah, as hoolio said, the button on the right above the iRule list is to refresh the list of iRules from the server. Keep in mind that this will wipe all the iRules you might have been working on locally and refresh them all. There is a "reset" right click menu option on an iRule by iRule basis but that will only reset it to the original value from the last refresh, not from the latest value on the server. I could add a single menu option here for "refresh" that will pull just that iRule down from the server if you think that would be valuable.
I'm not sure about checking for stale iRules. What time interval do I choose? 2 minutes? 5 minutes? 30 minutes? Whatever you pick, if you are working in a multi-user scenario, then there's the odds that you could overwrite each other regardless of the interval they are checked.
-Joe
Cirrocumulus