Hi BarbWire -
The Dalesbus services are to get kids to school, people from the remoter villages to towns with facilities (banks, shops, etc.) and yes, walkers to their start point for a walk and later, get everybody back again. So thus, they tend not to be over frequent and go largely from A to B. If you also want to go to C, that would, as you’ve correctly worked out, be a separate journey. Of course running alongside the bus service is the Dalesrail service and if memory serves, that timetable is included in the Dalesbus timetable booklet (incidentally there should be a summer version of this released any day now).
What I’d do as an itinerary is something like this. Travel to Gargrave by train from Leeds/Bradford/Skipton. Gargrave isn’t huge but it does boast a Premier Inn next to the Anchor pub. Overnight. Following day, walk up the Pennine Way to Malham (six miles tops. Maybe a tad more if you divert a little off route to the pub at Kirkby Malham). Overnight in Malham. See the Buck Inn, the Listers Arms and if you want to push the boat out, Beck Hall for accommodation. Also there will be some bed and breakfasts I think but nothing springs immediately to mind. Visit Janet’s Foss, Gordale Scar and maybe Malham Cove. Stay overnight again in Malham. Next day climb the over four hundred steps up to the top of Malham Cove and head up Watlowes dry valley to Langscar and head via Nappa Cross over to Settle. Stay in Settle overnight. Take the train next day to Horton in Ribblesdale to explore Penyghent if feeling confident or Hull Pot if climbing is not your thing!. Return by train to Settle by rail (or bus if timetable fits). Alternatively from Malham you can walk the eight or nine miles from Malham to up near Malham Tarn and then take Mastiles Lane (allegedly an old monks route) to Kilnsey in Wharfedale (Tennants Arms). From there you can take the Dales Way up to Kettlewell and Starbotton and beyond if you like, bearing in mind you probably have to walk back!). Overnight in the Kilnsey or Conistone area again and take the Dales Way to Grassington. Lots of accommodation in Grassington. Bus to Bolton Abbey and walk the Strid Woods and explore the Priory.
All just as suggestions cutting your reliance on infrequent transport a little. There are as many itineraries as you care to dream up. From Settle the railway heads back to Leeds/Bradford area (Leeds probably has better links to all points). From Grassington or Bolton Abbey you are not far from Ilkley (bus, taxi) which also has frequent trains to Leeds and Bradford.
One final thing. In addition to the relevant OS map(s) try and get a copy of Alfred Wainwright’s ‘Walks In Limestone Country’ a book that has given me a thousand golden hours in the area we are discussing! It might even give you some alternate ideas - basing in Ingleton or Dent for instance. Try and get the relatively recently revised edition (by Chris Jesty) as the original was written a long, long time ago and things will have changed here and there, even in the Dales. That the original is still the ‘go to’ bible for the area, speaks volumes of its genius!
PM me if you want to discuss/expand/need info on elsewhere, etc.
Oh yes finally - sensible footwear and head to toe waterproofs, just in case! I’m sure you’ll be able to cobble something wonderful together!