must (all) Muslims must accept the Sharia, or internalize and live - as required in Islam, or in Islam, non-Islamic systems such as democracy, capitalism, socialism, communism, humanism, etc. can internalize, Live and operate as a state form?
No, who should desire, control and possibly sanction.
No of course not. You can find it good or bad, like one popular.
The Sharia is mostly misunderstood. One of he says she is human, does not seem to know what Sharia is and what is not. Here is a link that explains briefly and flush what that is.
As Salamu Alaikum.
Yes , You need to. That's up and important.