The lined coat was initially adopted by the (mostly Muslim) Northern Indian aristocracy, but was later taken up by the general population. It is now the national dress of Pakistani men.
The coat is normally worn only on formal occasions.
Sadhus are wandering monks, who rid themselves of material goods and live a celibate life. They chose to live away from the rest of society, often in caves or forests in India. They spend much of their time meditating, in order to achieve the fourth and final Hindu goal of life, moksha (liberation). Sadhus often daub and dress themselves in ochre, as this is a symbol of reincarnation.
Fakirs were once the Muslim version of Sadhus, but the term is now applied to those who perform feats of endurance or magic, whatever their origin. Fakirs are famous for walking across beds of hot coals or sleeping on beds of nails to prove that the mind can overcome pain and suffering.
A bustee is a small collection of makeshift housing: a tiny slum.