Ok, let's get this straight: who will fly F in a regional or secondary airport? The demand is redundant, so please remove the F demand altogether when it's only less than 5 or so.
Also, lower F demand on short routes (like JFK-ATL or PEK-HND, it's like spam for almost every airline that flies on that route to offer F on that route). Don't remove it altogether though.
And then the C demand. It should be more at "business like" destinations than general "normal-low-cost" destinations.
Make F/C higher on premium routes (like transcon in US)