For Indians
1. There is no law that says forex trading is illegal. At the same time there is nothing that says that it is legal. Yes, there is a law that on an annual basis an individual can repatriate upto $25k from India. This to my mind can be used for forex trading. Also, as the rupee is appreciating, RBI might make it easier to invest in foreign currencies.
2. Forex trading income should be treated as a regular short term trading income and be treated accordingly. There should be no issue with your being in govt service.
3. Any broker having registered office and headquartered in the US should be safe. However one need to also be careful about the capital adequacy of the broker. Also, personally I need the Metatrader platform for trading as it really give me a lot of options to customize, set alerts, do some small programming etc.
4. As far as possible avoid brokers which have electronic currency as means of deposit / withdrawal, this is for your own safety.
Let me know if there are any more questions and I will be happy to help.