A.B.
My 22 month old is very similar... especially with the fuzz and cat hair on the stairs! She gets totally obsessed with any pice of hair... she can't just shake it off her hand... she has to yell "hair mama, hair mama!" Until I take it from her.
She also has to close hubby's dresser drawers and if a piece of clothes makes it not close perfectly, she gets upset until I tuck it in so she can close it...
Anyway, I am thinking it's ok. OCD is really only a problem (later in life) if it is gets in the way of living a fulfilling, and stress-free life. I think we all obsess over certain things the way we like it....
As far as how to help him not be so obsessive.... I was told to try to get her dirty with things like play-doh and sand boxes. So, you can try that.... but really, it sounds like all toddlers go through this.