I've heared that in some countries people have to pay the income tax after buying fiat for their bitcoins. Anyone faced such problem? If yes then how you deal with it in your country?
At one point of view bitcoin is an instrument for investment so ppl buy it willing to get income in their currency.
At the other point it is a currency and it might be used with a purpose of saving. In this case the tax would be stupid.
You need to understand this, as soon as you enter the fiat market the governments make the rules, that is the main reason why governments are going to try to stop the adoption of bitcoin so people cannot exchange their bitcoin directly that easily, if we get to the point in which you can exchange your bitcoin for almost any product and service that you can imagine then it's game over for the governments.