Everything is legal until the appropriate laws that make it illegal are established. Since the law decides what is and isn't legal, if there are no laws that say BTC can not function without proper regulations it remains legal. You are right thinking that BTC isn't a bank account nor stocks and since your wallet isn't assigned to your name you don't have to inform the government.
I hope that answers your question in full
I hope that answers your question in full
I very much agree with your position. In the law practice, it is said that you don't put something on nothing and expect it to stand. Thus, if for instance, a jurisdiction has not enacted a law that defines a thing or practice as illegal, therefore that should continue to exist as legal until the appropriate body declares it as "whatever" by enactment.