1) Tax laws are completely different for each European country.

2) At least for some of the countries (the once where I'm aware how taxes work) this is not the case: Even if you exchange one cryptocurrency for another cryptocurrency it's taxable. However, long-term capital gains of cryptocurrencies aren't taxable in some European countries.

In Estonia(within Europe) we have this awesome "investment account" system where you make a separate bank account and the tax system is simplified for that account.

Any money you put in, can be taken out without paying any taxes.

Once you've taken out more than you paid in, you just pay income tax and that's it.

You report your "paid in" and "paid out" sum(to/from that one account) to the tax office yearly.

Really makes the whole process simple and adaptable to any investment model.