we had a beautiful Contender horse put down and still have his ashes at our yard. A few times I have walked in the yard and he has been standing looking at me but as you walk closer, fades away. It's not spooky to me, more like he's checking up on his yard, he was a real character.
I would never count a "not a novice ride horse as dangerous". It simply should mean that you wouldn't put someone who hasn't been riding that long on board. I would never suspect it as dangerous? Maybe liable to a little buck or quite technical, things a novice would not cope with.