The Torah, which is the Five Books of Moses, is considered by most Jews to be the whole body of Jewish laws and teachings. In the Torah, there are six hundred and thirteen Mitzvot which is simply a commandment. That is a lot of chances to find the most important isn’t it? Some of them are Positive and some of them are Negative Mitzvot. That does not mean that they are good or bad. It means that they tell us to do something or not to do something. A good number of these Mitzvot are no longer possible for us to keep.
Some, because the Temple was destroyed and the Jews can no longer do the ancient sacrifices, and others because so many of us live in the diaspora and cannot follow the land mitvot. Also, long before it was common anywhere in the world, the Jews stopped all forms of Capital Punishment even though it was a mitzvah in the Torah. Keeping kosher is a mitzvah in Judaism and as it is a direct instruction from g-d which forbids a Jew from doing certain acts that a person who is not Jewish has the freedom to do. These acts include things such as not being able to eat certain foods and not being able to wear certain clothes.As keeping kosher is a mitzvah and they have been given by g-d, they all must have equal importance. Some may say that because some laws are practised on a more regular basis that other laws such as dietary laws and clothing may be seen as more important than other laws because they are not practised as regularly and therefore are not needed as much as others.
For example a man may not ever need to know that there are certain laws that woman should keep with wearing certain clothes in a certain fashion and therefore one may say that to the man those laws are not as important to him because they do not apply to him in the slightest.To conclude, the strongest argument is that all kashrut laws are of equal importance as they are direct from god and that even if certain laws are not practised as regularly than others doesn’t change the level of importance they have. It is important to recognise that some jews may not need to know all of the laws with regards to kashrut for example, a man will not need to know what clothes a woman must wear but that does not mean that those laws are not important no matter how relevant they are to the man.
Rather one may say it is the sum of the practice that is important.