A friend recently received greencard through eb3 a month ago. How long is it recommended to stay at the job before quitting/switching to a different employer

That's a case specific question but broadly legally there's no minimum requirement.

This friend has already worked for the current employer for over 4 years under h1b visa with at will employment type. In this case, is it ok to say it is safe to quit?

Can a F1 student start their own company and sponsoring themselves?

See my response above. After they graduate, it's much easier, OPT and under certain circumstances STEM OPT permit this.

Thank you for your response! Which type of greencard should be used by the startup LLC?

What options are available for a F1 visa holder to get greencard through his/her own startup?

The same as everything else. Green cards and visas are largely independent and one does not depend on the other.

can a US based company sponsor green card for an international manager has not taken the job yet ?

Who has not taken the U.S. job? Yes (if I understand you correctly).

Hello Peter, I have a friend coming from China and pursuing bachelor degree in America under F1 visa. What are some options available that can get green card as soon as possible other than the traditional route f1-> h1b-> eb3 ?

Is self-sponsorship an option?

You could always look at an E2 visa if you don't want to invest $800,000 in an EB-5 project; however, investment amounts vary from $150-400,000. The range is based on what USCIS would consider a "significant investment" based on your country of citizenship. E2s don't lead to a green card or US citizenship, but you may find a USC/PR spouse or another path while saving some capital.

Either E2 or EB-5 will have significant fees associated with them. Typical EB5 "administration/syndication" fees will run $80,000. You may be able to reduce this by going to the EB-5 Project directly and negotiating. Most of the time, 90% of that fee is used to pay a foreign agent(aka finder) for bringing the investor

Oh wait, China doesn't have a E2 treaty. You may still be able to find a way via Grenada but I am not sure that tactic still works.

You can look into EB-5 Visa if you want to self-sponsor yourself and have the monies: https://www.eb5united.com/eb5-visa/

With Priority Processing in Rural EB-5 Projects, seeing I-526E Approvals within 1-13 months: https://www.eb5united.com/updates/2024/02/eb5-green-card-in-...

Is there any limitation or challenge in sponsoring greencard by very small business and the risk of getting rejected?

As long as the company has the ability to pay the offered green card wage, green card sponsorship by small companies usually works. The main issues are unrelated to a company's size.

This could be just the beginning of bigger protests. As an American, I wouldn’t go to china even if I can, who knows whether I would be stuck in lockdown and cannot come back on time to work especially with all the layoffs going on in America.