Answer: East Pakistan separated from West Pakistan because of neglect and abuse on part of West Pakistan. East Pakistan was fairly lawless and forgotten by West Pakistan. East Pakistan had no voice when it came to its own affairs, as well.
Examples of neglect include:
The East Pakistani population was 58% of the total population of the country. This majority were not even allowed to have their language as one f the national languages until after a bloody battle between army and students.
Sub standard goods were sold from West Pakistan to East Pakistan at double the price. East Pakistan was not allowed to deal directly with any neighbouring countries
East Pakistani had no representation in the armed forces or in government or local office.
East Pakistan was very much in the same position as modern day province Baluchistan. Like East Pakistan, Baluchistan has an independence movement - the Baluchistan Liberation Army. It is fighting for independence for very much the same reason as East Pakistan did.
East Pakistan won their independence in 1971 and shortly after in 1973 the first Baluchi uprising started with a 55,000 man rebellion agaisnt Punjabi domination in Pakistan.
Answer: Originally, the practice was rooted in worship of the sun. With the sun rising in the east, it was presumed the same would occur to the soul, or spirit, of the deceased. Centuries later it evolved into simply the traditional method of burial, with little regard to the basis of the practice.