There may be a strong positive in that he may be excellent at "perspective taking" and Theory of Mind (ToM). I'd probably compliment him on this likely extension of his skill in this area.
Anthropomorphism or personification may also help fuel creativity in artwork and writing, for example a book from the viewpoint of the shoes, highlighting favorite wonderful adventures. I'd probably suggest this as well.
I'm not in a position to render a professional opinion, but personally would not worry unless the inanimate objects began to have aggressive, intimidating, or otherwise unsettling qualities... if his thoughts seemed to linger... or if his empathy was only toward inanimate objects, not humans, pets, other creatures.
Yes. Similarly with imaginary friends. As long as they aren't controlling, don't say anything nasty or negative to the child, or suggest that they do anything dangerous or destructive, I wouldn't worry about it. Just like with real friends, actually.
