What I am afraid of to happen, is the time will come that our transaction will be tax..
It will not be bad if you are allowed to use bitcoin legitimately and the government charges tax. There are countries that do not even allow to use bitcoins, so paying taxes will not be big concern as we have got practice to pay tax for what we earn/buy.
This thinking makes little sense! You correlate paying tax to opening the door for Countries that are banning bitcoin and that is a big unknown.
What is known about government and taxes is they tend to go a little bonkers on the percentage and regulate without understanding what they are regulating.
The idea that it "will not be bad" is the same line they tell people when something bad is about to happen and they do not want you to squirm.
Taxation will not bring freedom for bitcoin to breathe as a global currency,it brings regulations!
Can you explain more on why you think taxing bitcoin equates to more people using bitcoin?