I am a greencard holder currently living in the UK due to the coronavirus pandemic. I have a re-entry permit but I am concerned about taxes while I am in the UK. If I rescind my greencard will I have a more challenging time securing a non-immigrant or immigrant visa in future? I was considering rescinding the greencard and going through the H1B or O1 route in future.
You have to file a US but generally you can avoid double taxation, especially on the first $100,000. If you have business income it's generally a good idea to incorporate and have the company pay you to get the full tax benefits. Incorporation generally gives you a lot of flexibility tax wise.
If you abandon your green card you'll have to pay capital gains on all your assets as if you sold them, I believe.
PS: I am not a tax lawyer, but that's a quick overview