My goverment forbid bitcoin usage because it can be use for money laundry ( advantage for terorism activity )
So it has small chance for my goverment for bitcoin usage as the result bitcoin popularity can't grow like EU zone
It depends on exactly what kind of ban your government has imposed on Bitcoin usage. May I know what country you are from? Other than that, it basically doesn't matter for criminals whether or not the government have banned Bitcoin. They will use it either way as they can simply convert their coins to fiat back and forth via other countries.
Well, for my country it is not illegal but I can say that if you make a high amount of bitcoin and than exchange it for fiat currency they may ask where did you get this money from which might be hard to explain to goverments all around the world. So make bitcoin, spend bitcoin

,means do not try to encash it.
That is not really a problem as long as you earned that bitcoin legally, the only thing to watch for is the amount you will need to pay in taxes to your local government.