Could you clarify your question? Who left Romania? Do you mean the Romanies? (= the Gypsies). If so, I am not aware of any exodus; quite on the contrary, they are still here = (except those who left for the West after the Revolution = the fall of Communism = 1989).
No. Romania is a Christian country.
The capital of Romania is Bucharest.
Romania hasn't a true founder.
The western boundary of Romania is with Hungary.
The area of Romania is 238 391 km2.
What do you mean by this questions? If you refer to religion, Romanians are Eastern Orthodox. I was born in Romania, but I do not understand what you mean by "What do Romanias follow?"
Romania hasn't an official country flower.
Romania hasn't an official favorite color.
Romania hasn't a special theory on earthquakes.
After 1990 the economy of Romania was destroyed.
The enegy production of Romania is very modest.
For details see the link below: Statistical Year Book of Romania.