Does God want us to be obedient?

1. If God brought the Torah exclusively to the people of Israel, he apparently wanted a hierarchy of roles from which Gentiles are exempt. If a Gentile recognizes the value and contribution to the world (God's invisible religious goals) of the Jews and chooses to join, does this not violate the categorical imperative? After all, if all Gentiles were to join, there would not be the desired hierarchy.
2. If it were possible to do a (real) conversion from a woman to a man, would there be value for women to convert themselves and commit to the act that time has decreed? Would there be value for Israel to convert themselves to become priests?
3. Is there value in wearing a 4-paneled garment and committing to a tzitzit? The more tzitzits one wears on the body at the same time, do I contribute more to the world?

1-2. The categorical imperative, as far as I'm concerned, means that each person will act according to their own beliefs. The invisible hand is already taking care of the division between the different paths. Just as I wouldn't tell everyone to become a doctor because the categorical imperative says that everyone will engage in what suits them.
I think that a religious Gentile usually doesn't believe that if he converts, he will be in a higher spiritual status. A truly non-religious Gentile would be better off joining some religion.
3. There is definitely value in appreciating the commandments. There is also value in being a normal person and not letting the commandments fool you.

But do you believe that someone who walks with 2 tassels contributes more to the world/God than someone who walks with 1 tassel?

It seems so. And at the same time, non-normative behavior is harmful to the world and its inhabitants.