I have one scenario for selling my service to a small subset of an industry in US.

1. I’m a US Permanent resident but not a citizen.
2. I plan to run my business from overseas until i can validate that the business is viable.
3. My end customers(who will pay me) will be businesses.
4. It will be a free service for the customers of my customers.

So my question is ,
1. Can i do business without forming a business entity in USA as i might not have any permanent address in USA until my business takes off.
2. How do i pay taxes on my earnings ?
3. Can my clients pay directly into my bank account in USA or overseas for the services i have rendered to them? How do i invoice them? Can i invoice them electronically?
4. In case of any litigation (i know litigation follows success) , how/which country does that get handled?

I have a lot more questions but if you could give me some pointers on these , i would be very obliged.

Regards,