Travelling around Romania in early May (Bucharest)

I am going to be travelling around Romania in late April-early May. My sure stops are going to be Bucharest and Brasov, but the rest is still hazy. I intend to visit Sinaia for Peles and Pelisor.
What do you suggest? Is the Maifest in Sibiu worth it?
I have been suggested Sighisoara as well. Are the painted churches easy to reach for a carless visitor?

Thanks in advance.
(Ma descurc în româna, daca vreti).