1.The volunteering issue is a complicated one. When you are volunteering for charitable affairs or religious matters, I don't think there is any problem. The moment it starts getting into the realm of commercial volunteering it could potentially become an issue. Under the Fair Labor Standards Act (FLSA) private companies cannot take free work.
2. I personally think it is not a violation of your status. As for using your license for his company that could become problematic because the implication is that you are working for that company now. Remember under STEM OPT you can work for multiple companies, but you have to get approval from school for that.
3.The answer is Yes. Under OPT as well as under H-1B. As long as you have a genuine employer, employee relationship.
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Note: Unless the context shows otherwise, all answers here were provided by Rajiv and were compiled and reported by our editorial team from comments, blog and community calls on immigration.com. Where transcribed from audio/video, a verbatim transcript is provided. Therefore, it may not conform to the written grammatical or syntactical form.
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