Brockhall is definitely in catchment area for Clitheroe Grammar, the school bus even stops there.
Good point ! I think there are generally good local school bus services.
Only thing I would say is that some people in the area prefer some of the comprehensive schools to CRGS and don't take the 11 plus, even though I suspect they would get through fairly easily. Depends really on what the local comprehensive is like. Worth also remembering that CRGS goes up to year 11 on one site and then moves down the road to the 6th form where the year size more or less doubles. There are lots of options for 6th form in the area and there is quite a bit of moving around.
Clitheroe is generally a nice place and they are very friendly (even if i do live in Yorkshire