> I did the first option, but here is where I want to clarify if I did it wrong. This is what is in my vSphere SDK tools
yes, that's correct. You are adding your own event name to the white list of names used by the meta-data checker.
> Another question is does the requestHandler have anything to do with my action command.
Yes, it does. The requestHandler with the action id gets called when the action is invoked in the UI. To open and center a modal dialog then you can do:
var dialog = [the window with your dialog UI...]
PopUpManager.addPopUp(dialog, DisplayObject(FlexGlobals.topLevelApplication), true);
PopUpManager.centerPopUp(dialog);