At the moment, there is no easy UX way to have the component variable id, but you can just click on the explorer en JS mode to see it.
Please be carefull that the method to call is different for a local variable than for a global variable context.component.methods.updateVariable vs wwLib.wwVariable.updateValue
There is no way to call an internal workflow from a javscript code at the moment, but id is available the same way than the global one.