Well the "Yogya" word used here repeatedly in the show, they are showing that Sati is not yogya. They are mentioning that sati is not yogya of Shiv.
Well Devi AadyaShakti has taken birth in Daksh house as her youngest daughter Sati. She was dearest daughter of Daksh, as she was the boon of his tapsya. But the yogya word is not mentioned in any granth. Yes, she herself doesn't kill any asur as she was Sati and it is also true that she had fired her body in Daksh yagya.
The Question arises that why she go to Daksh Yagya when she was not invited?
As Goddess, its also her duty to maintain peace and save the truth, dignity and pride of the Trimurti. She cannot see any wrong thing with anybody and if it happens she has to stop it. Daksh wanted to insult Shiv and wanted to start a pratha where Shiv is not invited. To stop him, Sati has to go there.
She try her best to make her father on the right path. But Daksh doesn't understand and insult her and her husband.
She gets very angry on the behavior of the Daksh. As she is the daughter of him, she can't give him punishment as its against the daughter-father relationship, and the punishment is necessary 4 him. Then, she decides that not to be his daughter and want to burn that body which was given by him.
In many scriptures, it was mention that Sati was very eager to meet her family, sisters. As for the long time, she haven't meet them. When the we talk about God, god is free from all 'bhavnaye'. So why did Sati reacted this way?
There is a rule that whenever any devtas take the birth of human, he will have to leave his powers and has to follow all rules, made 4 humans. He can know himself only through the yog shakti. This is also true.
For Sati, is a different case, She is both human and AadyaShakti(goddess). As a daughter, she has to make her father on the right path, and has a goddess she has to stop him. She has a faith that she will make daksh on right path as she is his dearest daughter.
But Daksh doesn't listen to her. So she has to take some decision.
There are many danavas and asur's are shown. Did there really exists that time?
The All Danavas who was children of Danu and Rishi kashyap.
The all Asurs are the children of Diti and Rishi Kashyap.
and Danu and Diti are also daughters of Daksh.
But Tarakasur doesn't exits that time.
Who is Shukracharya?
Shukra was the son of Rishi Brighu. He has done his studies under observation of Angira Rishi. Angira Rishi was the father of Brahaspati. He has always face pakshpaat, from Angira Rishi, As Angira always consider his son Brahaspati instead of Shukra.
Due to this Shukra studies a lot and is more brilliant then Brahaspati.
Has Sati has done any tapasya?
Well, that time wishes are all granted by seeing the nature of the person. Thats why Aditi's Son Vivaswaan(Surya Dev) and Indra got that position. when we read all we will see that time all people were very much great and got engaged in work.