1) Yes, it's correct that you can get a residence permit after 8 years of living in Germany. For a list of detailed requirements that need to be fulfilled, please check out the following link:
2) There is an important question to be kept in mind: Why does the German state grant you a Duldung or residence permit? Because your home country is not able or willing to provide shelter for you. By going there you basically show the authorities that your life isn't in danger in your home country anymore. That's why I don't recommend going there even if you got a residence permit.
3) Traveling to India should be safe. You might need a visa, but apart from that I can't see a reason why you shouldn't be going there.
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