Yes, certainly you do! Just as Russians would need visa to go to your country
Well, it is
It might be useful if you ever intend to come back.
Yes, I have been there two times and the VISA getting was really bureaucratic. I wonder if it was actually easier to get into the Soviet Union back in the day.
Yes, probably, it varies with the country you are from and the country you wish to enter
That's why it is called the Irion certain.