EAD

I have an EB3 I-140-based EAD currently. If I set up a software firm for myself, can I sponsor EB2 or EB1 I-140 for myself? The main reason why I want to sponsor myself is I would not be under the constant fear that my employer may withdraw my I-140 for one or other reason. I will be able to work for myself. Is there any rule that stops me from filing an employment-based immigration petition for myself?

I came to the US in Aug 2015. Completed masters in 2017. Started OPT on 07/2017. When applying for OPT EAD I joined employer AZTech Technologies. I joined as an intern and was there for like 4 months. He responded for 2 months during training, after a couple of months employer did not respond at all. I got a doubt and found another job and moved to a different company. Later I got an H1B and I 140 approved. I am planning to go to India this August 2023. Recently I found out through social media that the company I joined in the initial stage of OPT EAD was a black listed company. Most people who joined those similar companies' visas got rejected when they went for stamping. I am going for H1B stamping. Will there be a problem in my case? Could you please advise me in this case? In an emergency situation, I need to go to India. I heard from some friends and social media groups out of my research that I can go get stamping done in other countries and then travel to India and can be back to the US. 

I recently renewed my green card EAD; the first EAD card expired on 04/2019. I had filed for renewal before the expiration. The USCIS provided a 540-day auto-extension based on the renewal application. Based on the I-797 C for renewal, the original EAD is valid till Oct 2023.

The new card is valid from Jan 2023 till Jan 2025. Will having EAD Cards with gaps in the start and end dates cause an issue?