I am an Indian passport holder. Can I enter Czech republic with Schengen visa issued by Greece? Are there any additional formalities/documentation required for the same?
With a visa valid for the "Schengen states" (in the national language of the issuing country) you can in principle enter any Schengen country.
You may not misrepresent your itinerary and intentions to get a Schengen visa, and if there is suspicion that you did so your visa may be annulled (cancelled). It is up to you to avoid this suspicion. With a multiple-entry visa that has already been used once for the reason it was granted, the problem does not come up. With a single-entry visa that has not yet been used, it is difficult.
For instance, if you have a 10-day visa from Germany and you arrive in France with a ticket to Germany on the next day, then you can easily show that you will travel on to your main destination.
If you have a 10-day visa from Greece and you arrive in Finland, making this plausible will be much harder.
Yes, but you must prove that you will spend the same or bigger number of days in the country that granted you visa, Greece. Otherwise you can be declined to enter. The proof can be prepayed room at the hotel, reservation of tickets from Czech Republic to Greece & finally from Greece to your homeland.