For buses I can make some calls in case you need to find the one going to Rosia Montana, for instance.
Sunday - 10 July
Sunday - 11 etc.
In terms of accommodation, I think it is your best bet on the way. I can send you some photos I took in April, if you want. The 'restoration' is not great, but it is not a bad place to sleep a night in.
Explore the Dacian Fortresses
For Costesti-Blidaru you need to hike about an hour up and maybe a bit less down on a path through forest. It's worth it, if you ask me.
There is a tentative site near Ramnicu Valcea (Byzantine Church).
Les « coules » de Petite Valachie (tent) is very close to Horezu, you might want to check that out. If you have the budget and they have availability, Conacul lui Maldar (which is a coule itself, not on the tent list) is one of the best places to stay in Romania. Also Horezu is famous for pottery, in case you want to buy gifts (or see how it's done).
Muzeul Satului (the Village Museum), open-air, if you like rural architecture.