Not particularly. Homebrew classes and races fall under the heading of house rules. Why do you?
Perhaps if Pathfinder were a pure 'point buy' system like GURPS. But it's not.
I think this particular area has enough overlap for a split to remain unnecessary and this forum gets little enough traffic as-is.
I believe in 2nd or 3rd edition there was a paragraph in a core rules book suggesting how to rewrite an existing class to becomes something new. I believe the example presented was rewriting the wizard into a witch by swapping out some flashy attack spells for some healing and restorative spells. So I think there is a place for it in a core rule book, but only briefly and in a very general way.
Well, one could encourage but couldn't enforce... adding [Class] or [House Rule] to a post title. It might just add more clutter, though.
You know what occurs to me?
It is really the SUGGESTION clause that does not belong. I know that there is a lot of house rules and suggestion overlap (i.e. "I don't like how rule X works; Paizo should replace it with rule Y" and then that is sort of a house rule), but the intent of the two are fundamentally different.
Suggestions should still go on another board, I think.
Really, suggestions not having their own board (or just going to the general board) is in some ways tantamount to Paizo thinking that community suggestions about game designs are beneath their notice (in the same way I don't expect Paizo is going to take my Prince class under advisement).