Will a denied I-485 hinder my chances at getting OPT a year later from now?

You should consult with an attorney if you are concerned with information you are obtaining from non-lawyers on the internet.

Can I change my status from case from H1B to B1, incase I get laid off from my work ?

USCIS will not likely approve a change of status to B-1 for inactive H-1B workers.

Interview of I-751

There is a strong likelihood your case could be denied, depending on what the letter said.

Immigration court

You can call 1-800-898-7180 and input your A#. Hopefully, you did not miss a hearing.

Do f-1 students have to file or pay taxes?

You should not be required to file income tax returns if you have no income. You can confirm this information with a CPA or the IRS website.

Can you obtain an Advance Parole to travel multiple times for employment reasons?

Yes, it is possible to request advance parole for multiple entries.

I485 - GC Interview pending

If your green card is approved on or after your second anniversary, the green card will be issued on a ten-year basis.

Does it violate the law if I work unpaid on my 17-months OPT STEM extension?

Technically, you should not be unemployed for 90-days or more while in OPT status.

Strictly passive investment is permissible, empolyment is not.

What's the next step after NVC administrative process.

The file should be transferred to the appropriate embassy to schedule the visa interview.