If my publishing developer account gets expired, than what will happens to my already published application. Will they removed all my applications or my applications will remains live? What if applications are paid, can I able to change the price?
Unlike Windows and iOS where developer is been charged every year(100$), android developer has to pay one time fee that is 25$ and then no further charge or fee.
But yes account termination due to various content policies, that can ban your account and your account will expire as it is.
and for reference you can check this link.