1) Do I need a Visa to travel to Greece?
Greece, like every country, has made arrangements for granting access to the country based on mutual agreements between Greece and your country of origin. If you are not familiar with the agreement made with your country of residence you can visit the official site of the Greek Ministry of Foreign Affairs in order to obtain all the necessary information. http://www.mfa.gr/en/visas/visas-for-foreigners-traveling-to-greece/
In the case you need to get a visa issued it is important to note that you will need to make the necessary arrangements ahead of time by contacting your local Greek consular authorities and not leave this pending for the last minute as the process can take several days to complete.
2) What currency should I choose for my transactions?
Greece is a member of the EU. Therefore, the official currency is Euro as for most European countries. If you haven't converted you currency before your arrival in Greece that is not a problem. All Greek banks as well as exchange offices can easily and quickly exchange your national currency to Euro using the official exchange rate. You can also use credit cards or traveler's checks.
3) How safe is a trip to Greece in view of the "crisis"?
Greece is an ABSOLUTELY safe country for anyone who chooses to visit it. The crime rate is practically nonexistent for foreigners visiting our country, and the occasional petty cases concerning tourists are the same, more or less, as in any other country in the western world.
In terms of social reactions, demonstrations and protests that are occasionally described dramatically by the media, by no means are they related to tourism nor do they affect your secure presence in the country. The only side effects you are likely to experience during days that such events take place are an increase in traffic and certain strikes when it comes to public transportation, but these are elements that do not affect organized travel groups. - See more at: http://grazytravel.com/page/Questions#sthash.bVCzMmnD.dpuf