1- Is to work in bank, investing, and taking interest of bank accounts in our today societies OK?
Seeking interest in bank accounts, investments and working in this field is an active process where you want to gain more through violating a Qur'anic principle, namely riba is not allowed, so it is not OK. Living in societies where every day you come into contact with the riba system is unavoidable but if you limit this to what you cannot do anything about it, then this is acceptable until the system changes.
2- What about those who will live in a non-Quranic country when there is a true Quranic State somewhere?
There is no Qur'anic state but if there was one then the whole of the 'ummah' cannot go there so answer to question 1 still applies.
When the Qur'anic state does re-emerge, it will make for a better life for everyone, so more and more 'countries' should sign up, however, as with the world today, this may never be universally accepted.