Trading in India ..help please

#1
Hello
I am interested in knowing more about Indian markets for NRI
1) What is the max leverage one can get for day and long term equity trading?
2) Is selling of options ( to open) both covered and naked allowed?
3) Can one get Non recourse loans to purchase shares in India? ( similar to these one in Australia http://www.leveraged.com.au/products/tailored_equities_multiplier.asp#what
4) Is short selling allowed ( both day and long term)
5) What is the safest way to open account ( safety from broker default and fraud)
Appreciate help
MJ