If an American starts a company in Dubai which has no presence in the US, will the company pay US taxes?

It depends on where the corporation (or comparable entity) is chartered, how much the owner pays in taxes elsewhere, and what profits are brought...

If I get a court order from outside my home country, do I have to comply?

This sounds more like an issue where a lawsuit is underway and the judge hearing the case is compelling you to produce evidence. The short answer...

Can I apply for us citizenship

You can't serve on a jury if you aren't a citizen. Whether you can apply for citizenship is unrelated to a jury summons.

If you're a US citizen, you should have no worries whatsoever. ICE can't do anything to you. Not legally, anyway.

If the NDA is properly drafted and authenticated, sure.

What is the "law" regarding the US dept. of commerce/census bureau?

No. It's not. Very likely, just based on what you've indicated here, it's a scam. Google "census bureau mail survey" and you'll see a whole...

Is there a way to attend a mandatory Florida mediation in Europe?

My colleague is absolutely correct-- mediation happens by videoconference all the time. That's the beauty of mediation. It's a voluntary process...

Does the 14th amendment and it's equal protections clause protect non-citizens of the Unites States just like citizens?

Not just the 14th Amendment's equal protection clause, but that of the 5th Amendment. They apply to *persons*. Not just citizens.

Can a US citizen be forced to leave the United States in order to testify at a military trial?

She can be compelled to testify, yes, but not necessarily in person. She may be able to insist on testimony by videolink, but she'll definitely...

My colleague offers the best suggestion. That list is right here: https://caracas.usembassy.gov/lawyers_list.html