How do I proceed?

Agree, sit down and work it out. Or, walk away, which you indicate isn't an option, so focus on approaching with an open mind and not defensively....

Can I sue someone for going on social media and spreading rumors about me ?

Report the posts to the platform, FB, etc. You can always sue if want to spend tens of thousands of dollars. You also would have to show...

You should be able to, but will depend on the local (city/county) rules, check with office where you obtain occupancy permit.

How to complete form 1120 and schedule C, K, J for startup under 250,000$ in assets?

This is really an accounting questions you should discuss with your CPA. Filing is usually based on revenues, not assets.

Yes, Customs Duties apply to all imports, does not matter who the importer is. If you are unfamiliar with the process but the item is...

Is it illegal to realize and keep a gain on money given to you by another person?

Probably not, but maybe somewhat unethical. You did use their money for your gain but arguably that was consideration for holding the money for...

Operating as DBA under LLC provides liability protection?

You can register the assumed name for the LLC. You want to operate under the LLC. The entity (LLC) provides the protection, not the DBA.

Extradition treaty for someone who kidnaps a child

It could be, but will depend on a police agency or prosecutor pushing to have extradition. It will depend on the treaty with a particular country...

Can I get proof that my husband from India and I have no dependants for the immigration process?

You do not need to prove you have no dependents. It is irrelevant to the process. Simply list n/a or none anyplace it asks for names of children.

How long can a US citizen live out of the country to move to Nigeria for 2 years?

If you are a US citizen, you can stay out of the US for as long as you like. Forever even. There is nothing you need to do. For security you may...