Take a look at the Event Engine app...it should be able to do all of this in one "cog."
And as noted use HSM to provide an arming alert if anything is open/unlocked.
Nice thing about Event Engine is everything is point and click, super simple.
Create a virtual switch (mine is called Nighty-Nite) that ALexa triggers via your good night voice command. Then trigger the Event Engine cog w/that switch turning on and it takes care of all the actions.
