2 weeks in Romania itinerary advice

Hello everyone,

I'm planning a trip to Romania in August and it's the first time in my life that I am trully undecided on what to do so I'd really appreciate some help. There are a few things that I have decided and these are that I don't care spending time in Bucharest (I can do it as a city break if I want to), I have to go to Targu Jiu (since this is Brancusi's year), I want to include some days for relaxing between siteseeing and I've accepted the fact that I can't do everything so nothing else is unmissable. Anyway I've made quite a few potential itineraries and I'd like some input if anyone has it (I will do a brief description so I won't take much space and time). I should add here that I'll be using public transportation...

1. Arrive in Bucharest and take the night train to Cluj, spend the day there and then to Sighisoara for the night. Next day go to Viscri, stay there. Then Brasov for 2 days (including Peles castle) and from there 3 days in Sibiu (for ASTRA and Balea Lake). From there go to Olt Valley (Calimanesti or Ramnicu Valcea?) and the next day to Targu Jiu. From there to Deva (for Corvin Castle) and then Timisoara and a night train back to Bucharest.

2. Arrive in Bucharest and take the night train to Tmisoara, spend the day there and then to Deva for the night. Next day visit Corvin Castle and then to Targu Jiu. From there go to Olt Valley (Calimanesti or Ramnicu Valcea?) and the next day to Sibiu for 3 days (for ASTRA and Balea Lake). From there go to Biertan for the morning and then to Sighisoara for the night. Then Brasov for 2 days and Busteni for 2 days (for Bucegi Mountains). Last morning a quick stop in Sinaia and then Bucharest.

3. Last itinerary is the same as the second but instead of going to Timisoara, go to Craiova, spend a day there and use the extra day for Sibiu. This way I have 4 days in Sibiu that allows me to visit Corvin Castle from there and possibly one of the nearby villages like Sibiel.

Thanks in advance for the help and I'm open to any other suggestions