I'll reply again since I like you and want to see you live and/or at least not covered in poop dirt.Everything is a safety issue when you start modifying a vehicle. It's not as if this didn't cross my mind. Of course it did. I'd be more concerned with your hacking of the factory suspension and driving on public roads putting other people's live at risk. And it's funny how people react to this. A lightweight axe and shovel = DEATH upon all passengers but nobody says anything about the heavy compressor. What if that thing breaks loose in a rollover? Surely could cause more bodily harm than a 3lb axe with a plastic sheath (nothing more than a plastic stick at that point). Or the ice chest held down with a few straps. What about the dog? He's not strapped down. That's an instant 85lb projectile.
The pointed end of the shovel pointed at the back of your head seems unnecessarily risky. If you rear-ended a semi truck, everything is going to want to move forward. Most of your cargo is going to be captured by the seats themselves. Admittedly, the shovel will probably stay put too, but if it does break free, it could get uglier than it needs to be.
Lastly, you're talking about a poop shovel and putting the business end of it near your head. I don't know, man, store your sleeping bag, pillows, clean clothes, stuff like that up there.