I suppose my screen name gives away my bias...
LOL I don't suppose you're biased towards the Mauser either?
Actually the Vulcan's are fairly safe because the fire voltage/current is controlled with mechanical switches within the firing circuit itself and not just in the control circuitry. Obviously any number of things can go wrong but unless the barrel drive motor is turning, it's almost impossible for the Vulcan to have an accidental discharge. Zuni's and other similar devices having very poor transient & induced current protection were far more dangerous as was made quite evident in 1967 onboard the USS Forrestal.
Seriously, my bias toward traditional ML's and especially flintlocks has nothing to do with my comments as they relate to this particular rifle - my comments are based solely on the lack of reliability within electronic devices with a control side that is separate from the discharge side when there is no mechanical interlock within the discharge side. Anyone who has worked around strobe lights that operate on the same principle as this rifle knows full well the occasional unitentional flash of a strobe that is turned "off". Construction and emergency service workers know about this because most often the flash of the light is triggered by a cell phone or portable radio being used within proximity to the light that has been effectively disconnected from the main power source on the "control" side of the circuit. Sorry, I trust devices with this kind of circuitry about as much as I trust beating on a Mk84 fuse with a 3 pound hammer.
As for the air being compressed, yes it can cause issues depending on how well the bore is being sealed off by the item you are trying to ram down it. Anyone who has an ML shotgun or uses a wad under a solid projectile in a ML rifle has seen the effects of compressed air pushing back when loading. In a ML shotgun you have two options, insert the wads only far enough to allow building the entire projectile load at the muzzle and pushing it all down together or cutting a notch in the side of the OS wad to allow the air to vent past it as you push it in. Same if you use a tight sealing wad like a nitro card under a roundball or conical, the wad will effectively seal the bore and if the projo also seals the bore good enough, it will take time and constant pressure to get the projo seated until all the air bleeds out - otherwise the projo either won't seat fully or will get pushed back out of position as you remove the ram rod.