Czechs use Czech Crowns (CZK) - Koruna in Czech language. In the recent past they have also used Hellers (haléře in Czech) as a 1/100 of a Crown.
One Crown is about 25 EUR, 18 USD or 30 GBP.
none
Czech republic
Currently still Czech Koruna Somewhere near to 17 Koruna per dollar 10$ is 170 CZK
Ceska Koruna or in direct translation: Czech Crown.
Germany
Official name is Czech REpublic but if you want you can reffer to it however you want. Some suggestions easier than Czech Republic are Czechia or Czechlands, or if you want to sound smart you can use one of historic names such as Lands of the Bohemian Crown.
Anonymously
Czech Republic still uses its own currency the Czech crown (or Česká koruna, CZK). While you can use EUR in main tourist spots and some supermarkets it is NOT offically accepted currency.
Money is better. In Czech republic homeless people use magnetic parts of old laudspeakers to "fish" these coins which help them to survive.
In larger cities, such as Praha, Brno, Pilzn, and Ceski Budejovice, it is possible to use euros in tourist oreinted places. However, outside of the tourist center, it is usually impossible to use them. It is best to convert foreign currencies to Czech koruny, which is the accepted currency of the country.
No, but there may be other restrictions on use.
Czechoslovakia doesn't exist anymore. In both Czech Republic and Slovakia you can use "Ahoj".