We’ve lived in Clitheroe for close to 40 years now. It is still a nice place, but has changed drastically in the last 10 years or so as far as development and infrastructure are concerned - there are far too many new housing estates off roads which are unavoidable bottlenecks, so traffic in and out can be dire at peak times. (If you come here to look at houses, avoid Henthorn Road and Waddington Rd!)
The villages are popular but for me their access roads rule most of them out - single-lane bridges with poor sight lines, or very narrow roads/tight bends. I always get twitchy if I just have to drive to one of them; I’d have a nervous breakdown if I lived there!
My kids are grown up and have left so I don’t know much about teenage activities. I have heard about drugs being an issue here but couldn’t say if it’s any worse than anywhere else, or if people make a fuss because it’s worse than it used to be. There does seem to be a rougher element now too - more vandalism, which is sad. I think it is true that (outside sport) there isn’t much organised activity for them.
I can’t comment on the secondary schools these days either, but both Ribblesdale and Bowland have good reputations, and have always had much better pastoral care than CRGS. (There’s also St Augustine’s in Billington, which is RC but does take some non-Catholics if there are spare places.)
Housing here is actually much less expensive than both Ilkley & Holmfirth, going by a quick look on rightmove. (Houses away from the bottlenecks get snapped up though.) Train service to Manchester is pretty good, and you can also access trains going to Yorkshire if you change lines at a station further down (I never get trains but DH does)
As you said, Ribble Valley is very beautiful. And nowhere is perfect! So definitely come and check it out 