How can I extend my staying in US?

I hope you are not planning on continuing to live with your host family once you get the F-1 ... that is an almost certain guarantee for a...

TPS—-> AOS?

Talk to an attorney ... entering on an AP doesn't "solve" things.

Yes, you will face issues ... unless the employer fulfils their promise to pay you ... starting October 1 ... they can not 'bench' you without...

What is the procedure for immigration for J1 visa holder short term visiting scholar?

Although you might be able to apply for a tourist visa to 'bridge' the COVID-19 gap ... talk to the school about getting a new J.

I-864 Financial Requirement for permanent resident's spouse

Q 1: Can i also attach my foreign pay slips? A: You can attach them ... but, no ... they won't be considered. Q: 2) I do not have a joint...

Yes, it is possible for a family friend/relative to become your guardian.

Can I get married here in the US even if my tourist visa is still pending/processing?

Your facts are confusing. First you mentioned an internship (J-1? H-3? something else?) Then you mention a tourist visa extension. You...

Please be more specific. What will he be eligible for in 1 year?

Can I be able to file for EAD without having gone for my biometrics?

150 days? Did you file for an EAD based on an asylum application? If not, please be more specific.

Grandfathered 245l

You need to talk to an attorney in private. I'm not so sure that you qualify for 245i.