Yes, we all know Leia, Obi, Luke survive etc etc...and spoiler!! 3rd sister is clearly one of the younglings taken when the temple fell. Thus her grudge against the Jedi and obi. Clearly, the empire abused her in the process of turning her.
Is the acting always good...no clearly not. Is it Shatner like in scene chewing...yes it is.
Just sit back and enjoy it. It shines alittle more light onto what Obi was doing between clone wars and a new hope. It's not going to be a master piece but it's head and shoulders better then Book of Fett which was awful, the best esp of that being when Mando showed up.