There are plenty in the UK - they are Parsees from India. An old cinema near to where I grew up has now been converted into a Zoroastrian cent re. I know a few of them and they seem like really nice people.
Probably. The Quran?s graphic portrayals of heaven and hell; its instructions regarding a Kublai or direction in which one should turn when praying; its rules regarding prayer and purification; the idea of the use of balances on the judgment day and of Al Araf or purgatory; the opening prayer of all auras except the ninth, ?In the name of God, Most Gracious, Most Merciful?; its angel ism and demonology, all find their close counterparts in the Talmud of Judaism and the Avesta of Zoroastrianism.
Yes. Not many, but some. India and Iran have the most adherents, but there are proponents throughout the world. I recall reading that there are fewer than 200,000 Zoroastrians in the world.
Yes. A community known as the Parsis still practice this faith and are present in India today. They fled their homeland (Persia) long ago to escape persecution and had ended up at the Western part of India several thousand years ago. They've assimilated into the local culture very well, but still maintain their identity by having a strict code of conduct that prevents marriage outside the community.