Your definition is much closer to Rawls’s vision of a just society and the “veil of ignorance.” While heavily influenced by Kant, Rawls comes much later.
Kant’s Categorical Imperative was an attempt to define moral laws (without resorting to a deity). The article has it right, though I might change the wording slightly to say that a “rule” or “law” that I use to guide my behavior is only moral if its universal adoption would make the world better.
Choosing to be a philosopher is not a rule. Something like, “I should never lie” is a rule which one could evaluate with Kant’s approach, by asking whether if everyone followed that rule, society be better off or not.
