Is bitcoin money?
No. Nothing is priced in Bitcoin. It is at most a clearance system.

Should money have rules?
That is a too broad of a question.
All economic systems are governed by the rules of economics.
Government create rules. Some good. Some bad.

Or money can end up becoming something else?
Gold can become jewelry....

Should bitcoin have rules that enforce it to be permissionless money?
Only if you want it to be freedom money. But for that you have Monero.

Or bitcoin is software that could become anything?
It's a Blockchain. By definition. So it can't be anything.