As one of the Mods, and having experience of the way things are run on other Fora both Masonic and General, I would be very diffident about setting out a Forum "Ten Commandments" or "Book of Constitutions".
Obviously if Staffs, our Founder and thus "Primus inter Pares" wishes to set out a Body of Rules then so mote it be, but otherwise I would dread that these could become set in tablets of stone and stiffle free discussion, as for example too rigid an insistance on "Relevance" to the original posting in a Thread can cause.
To my mind the normal Rules of Discussion and Good Conduct should obtain, no personalised abuse, no defamation, religious bigotry, obscenity. Indeed, if you would not say it to the person face to face then one really ought not to post it.
Otherwise the Moderatorial rod is lightly applied here and let free discussion and discourse ensure.
On the more specific point of what goes where, I agree that it is sometimes difficult to decide if a matter is Mundane or Esoteric , so post it and if its quite definitely in the wrong slot or starts to veer in a particular direction it can always be moved later.