In reply to Ian Butterworth:
The trouble with danger symbols is that a route either gets one or it doesn't, which can be taken to mean that the route is either dangerous or safe - it's black and white. I think that at a place like FCQ a more nuanced method is helpful, since a large proportion of the routes have at least some degree of looseness and could potentially be daggered.
While checking for the last guidebook, I set myself the task of climbing (on lead wherever possible) as many of the routes at FCQ as I reasonably could, including many of the obviously looser ones. I had several alarming experiences, which were by no means confined to the north side. The one time I actually injured myself in a significant rockfall was on an apparently solid north-facing area of slab (right of Withy Crack, on the route Boner).
Therefore, (in collaboration with Mark) I did try to keep in mind a sort of comparative scale of looseness, rather than being indiscriminatingly horrified by anything that wasn't a north-facing slab!
We settled for reserving the XS grade for routes which were pretty much loose throughout, and tweaking the adjectival grade upwards for routes with easyish climbing but sections of untrustworthy rock. The looseness is also mentioned in the route descriptions, of course, and there's also a prominent extra general warning in a red panel in the intro. I suspect that if the relative novices you mention aren't put off by those things, they'd be likely to disregard a dagger too.
That said, I can see the case for several more routes going into the most dangerous category (dagger/XS/grey panel - or whichever system Mark et al decide to use).
Perhaps there's a case for a tiered icon system to reflect looseness - like the smiley faces GWR use to indicate the friendliness of the bolting on sport routes.