There is nothing like minimum capital. It depends on your risk apetite. Anything above $500 (Rs. 25000 approx) is a good amount to start with.
Always use less than 10% of your capital as margin (Most important thing is use of stoploss - Markets can be irrational, longer than you can remain solvant).
Good training before you start trading, is equally important. Disciplined trading after start of trading is vital.
Deposits and withdrawals are also as easy as your indian trading accounts if you follow certain guidelines.
There are no clear guidelines on IT part, if you really earn that much profit better to pay as per Personal IT slabs to avoid any complications later.
All these are small hickups...when compared to potential of returns... all you need is discipline and good training & guidance (atleast initially)