The torah of Israel belongs to the people of Israel - it amazes me all the time how people from outside the faith come to the people of Israel and explain them "you made a mistake" that's like telling a samurai he doesn't know how to make a sword, telling a kung fu master he doesn't know how to fight.
we are talking about traditions of hundreds if not thousands of years carefully passed down form generation to generation.
One of the 7 seven things of a smart person is on what he does not know he says "i don't know" the opposite is in regards to a "גולם" ... (source: ethics of our fathers - פרקי אבות)
we are talking about thousands of years, generation to generations, if there is changes there are very good reasons for it, and you can rest assured it's according to the book, and for the sake of it's preservation. in order to have an opinion you need to be on a level of learning that is very high, only than is your opinion even valid, if you just found out 2 weeks ago who Rashi is - you still have a bit more time until you can have an opinion.
We do see however, that sometimes Jews behave in a way that is a disgrace to the torah and the Jewish people - if they are not religious than can we blame the torah? not really because these individuals - of their free choice - decided not to go in the way of the torah.
but what about the ultra orthodox Jews who behave disgracefully ?
1. Being that Judaism is a free choice system as the torah says: "i give you today the life and the death - chose life" we need to accept that every man has free choice - and this choice carries heavy consequences - the torah can guide - but if a man is not sensitive - he will do good things in a evil way and think he is doing good.
story: there was a stingy rich guy who heard a knock at the door, there was a poor man begging for food - so the rich man gave the poor man some rotten fish to eat - the poor man got sick from the food - the rich man brought him in - and was with him till the poor man passed away a few days later - the rich man than arranged for the poor man to be buried, later he turned to his servant and said, look how many mitsvos i did with just one rotten fish! (feeding the poor, visiting the sick, burying the dead...) obviously the rich man was delusional about his "mitzvah count" but he failed to see it due to his unsensitive nature,
The evil inclination can disguise himself to seem holy and pure - and tell the person all kinds of justifications for doing sins.
We know that this ongoing problem has been addressed through the ages, the alter Rebbe - 7 generations ago and the first rebbe of Chabad - wrote Chassidus and many books like the Tanya - to make clear that someone who wants to be a "Tsadik" can only do so if has love for his fellow man - and no matter how smart one might be - if you hate the kids - you hate the father (Hashem).
Humans are not perfect - far from it -the torah is here to help, but it can only fill a vassal who is not already full of trash...
of course on the personal level, every human being must CHECK HIMSELF all the time to see if he is truly doing Hashem's will - or is he blinded by arrogance and self image.
the torah itself has built into it - room for explanation, but this is a skill only a Beis din can attempt, preferably a Sanhedrin of 70 Scholars, of course the whole torah is filled with " g-d said to mosses say to the children of Israel" in the torah itself you see that the oral tradition is built into the torah. and understanding of the torah is incomplete without the oral tradition (the Talmud, halacha and so on).
the torah is a book of laws, does everyone follow the law? no, but these laws are not man made, they are g-d sent, we need to see how they fit into our lives - the Jewish people were at mount Sinai they heard the torah from g-d's mouth, they have been following the torah in practice ever since in a unstoppable chain. this should not be taken lightly.
the Jews have a mission, to be a light onto the nations, they will gladly get to work if the nations allow them the peace of mind to do so.