I bet your neighbors are sooooo happy you moved in. The improvements to the yard are astounding!
I can't stand snakes either. If I see one my heart jumps like a popping balloon. Even worse I can't stand looking at snakes. I forced myself to learn about them. I am not healed by any means but I can get a snake to move out of my way fast. If it doesn't move fast enough. It's dead.
My suggestion is if you cannot possibly move the rocks yourself, give it away. I have used Freecycle and offered things up as "You dig it" and someone will come. It's free and they will dig it up. We got rid of my neighbor's large shrubs that way and my large over grown Sego Palm, too. Some folks aren't afraid of a little labor for free things.