Should chess topics in off topics forum be allowed  ?

No.

1. d4

of course not. such actions can only lead to complete anarchy!

We need an Off Topic Once Removed Forum to move such topics to.

Yes, it should be definetely allowed. It depends on the title of the topic and the purpose of the discussion.

What if the topic was about chess and mouse or rats maze? Not really related to chess moves and games played or tactical play.

This topic could talk about the complexity of the chess game compared to a rat trying to find it's way out of the maze.

i am not sure there is a forum catagory that would be approriate for that one. 

 The category  could be General Chess Discussion or Off Topic. Take your pic.

Alternatively a new category called Chess and It's Environment could be created as a new Green category.

that was an attempt at humor.  but, i was thinking more along the lines of "unanswered posts" for the chess rats in a maze.