Hi there ^^
For the question one, you have an option in the plugin for you to set any key that you want from your keyboard. Including if it is not any of the default ones from mv. Take a look at the parameters below. For the keyCode you have to enter in a site like this one. Type any button that it will give you the code.
For the second question, you have to active the event just like you do with the Z key. So the event has to be with the Trigger set to "Action Button". The differenc is that when you activate an event with the extra key, you can customize the event for execute different commands, that it will be not executing if you active them with default Z key.
Got it? :)