Like, open account somewhere as a native of St. Kitts, receive income there, live in your home country of Germany-France-whatever and claim you don't have any income so no tax? The bank would report the account to St. Kitts... Well, it should work just until it does not - the bank may request your second passport at any moment, then all get reported back to Germany-France-whatever and they investigate you for evasion... Not sure if it is good long-term plan.