Bordeaux or Toulouse, there is no one better than the other since the two cities are very different.
The problem with people who want to go to Dorgogne is that they think that Sarlat is a good centralized place to visit the Dordogne (thanks to Rick Steeves) whereas Sarlat is located almost in the far west of this region which includes also the Lot, Lot-et-Garonne, and Correze départements located further east.
Taking this particularity into account (and as a resident of this region) I think that Toulouse is a better starting point than Bordeaux to go to the "Dordogne".
If you want to go back to Dordogne I would advise you to find accommodation in the Dordogne valley located further east than Sarlat.
So you can visit other places classified among the most beautiful villages in France such
Collonges-la-Rouge
https://www.tourismecorreze.com/en/tourisme_detail/collonges_la_rouge.html
Martel https://www.martel.fr/
Carennac: https://www.tourisme-lot.com/les-incontournables-du-lot/plus-beaux-villages-du-lot/carennac
I agree with acraven about Rocamadour which has for a long time not only been in no way a place to stay but also a place with its dozens of coaches crowded with tourists who arrive every day and leave after having a drink or had lunch in tourist traps and bought souvenirs made in China.
Regarding the 100 Years' War castles you have already mentioned those of Beynac and Castelnaud.
You can add the Commarque Castel:
https://www.commarque.com/
and the Excideuil Castle:
https://www.perigord.com/listings/sites-touristiques-visites/chateau-dexcideuil/
And if you are a castle fanatic, here are some others in the region:
Montal Castle: https://www.chateau-montal.fr/en
Castelnau-Bretenoux Castle: https://www.castelnau-bretenoux.fr/en
Vaillac Castle: https://www.chateaudevaillac.com/
Larroque-Toirac Castle: http://www.chateautoirac.com/
Lantis Castle: http://www.chateau-de-lantis.fr
Assier Castle: https://www.chateau-assier.fr/en
Bonaguil Castle: http://www.chateau-bonaguil.com/en
Turenne Castle: https://www.tourismecorreze.com/en/tourisme_detail/turenne.html