Firstly you must understand the position of the parent in the eyes of Allah. And although their methods may be perceived as harsh by you and your siblings; from what you are saying they are acting in your best interests.
I can’t see any grounds for you wishing to leave the home, all you are doing is running away from one trial to a harsher one.
If your sister wishes to remove her hijab this is not due to your parents but more to lack of faith. Would you stab yourself because you hated your neighbour? This is pretty much the reasoning your sister is using to disobey Allah.
Allah is pleased when your parents are pleased and angered when they’re angered.
You need to listen to your parents and be a good and obedient child, because by what you have stated your parents are religious parents. Parenting is not an easy task, if you upset them you will suffer in life and then the hereafter.
Now, this is how you should deal with the situation, you should sit and talk to them respectfully and if they insist you must accept their wishes.
May Allah guide us all.