B-1 Visa

The government will say as one has overstayed their I-94, they will now be subject to section  222(g). If you overstay your I-94 the visa stamp on  your passport is automatically canceled, so you have to apply for a new visa. For more details on this issue, visit my author page on The Economic Times.

1. There is no need to withdraw the application, but if you want to withdraw you will have to send a letter. Even if they leave without getting an advance parole the I-485 is deemed to be abandoned but the I-130 can still go on. You will have to call USCIS to open a customer service request and convert the I-130 to consular processing. Even though the I-485 is abandoned the I-130 is put in the consular processing queue.

2. If they leave before November 30th their visitor visa should not be affected.

I have known many immediate relatives of the U.S citizens and they have never had a problem. However, theoretically the problem exists. It would be right to do an immigration pre-clearance somewhere close to home.

Regarding your query on medical emergencies, you could tell them that your parents took the medical treatment. As long as there was no government funding I do not see any problem.
 

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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.

I would strongly recommend against it. I think you would do a lot better trying to get an H-1B Visa stamping in a third country. People are going to places like Singapore, Hong Kong and Maldives. Look around India and you might be able to make an appointment. 
 

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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.

1. Your obligation is complete when the government physically receives your papers with the proper filing fees. After that, if they delay in creating the receipt it's really not your problem. As long as you can show that the papers were sent and received by the government. 
2. The answer is No. Let's say that they did leave, then they’re I-130 would still go on but their I-485 would be abandoned and you would have to convert the case to consular processing. 
3. They are automatically eligible to stay because once their I-485 is timely filed, they are considered to be an authorized period of stay. They cannot be illegal as long as the I-485 is pending.  
 

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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.