I have a 500 set up with a pistol grip and white light for home defense. These are my thoughts, FWIW....I think you're going to want to 'weld' your firing hand back to your hip or the side of your torso for stability while using the spot beam or the laser to do the aiming. If you train that way, that's where the weapon will be when adrenaline starts flowing. Anyways, if you dry fire rehearse for awhile, you'll see it's not too difficult to operate the 500's safety.
Alright, this is just fancy car camping, people. Move along, move along.