bike insurance for India and Nepal - how and where ?
Not sure about Nepal but ask around Karol Bagh in New Delhi and you're sure to find something. In India, it is the vehicle that is insured not the driver and 3rd party is mandatory, cheap and probably useless, accept to remain within the limits of the law.
As for accidents, yes things can turn nasty very quickly and the only advice would be to rely on your gut feelings; if something feels as though it is going to get nasty and you can get out, then the best thing might be to clear off and report the accident at the nearest police station, and possibly notify your embassy.
Usually accidents result in big crowds and sometimes they dish out beatings', or worse, to the perceived person of liability, and as someone correctly observed, this will usually be you. I'm not sure if it's true or its an anecdote, bit I heard of someone who had a prang with a scooter and when the plod turned up, he tried to explain it was the other parties fault, to which the policeman said 'but sir, it is the fault of you, for it was you who came to India'.
Take real care in India and drive as slowly as you reasonably can. India is probably the most compelling place to travel and certainly one of the most bizarre. It is also probably the worst place in the world to travel by road and one of the most exciting as well! Boredom is a defunct noun in that country, I love it there. I would be happy to impart advice or offer hints about places off the beaten track should you PM me.
Best of luck,