Need legal advice on taking a Californian Attorney to court for malpractice. Need to know what of the following is illegal and what is not, with links to your research.

This is about federal, California and Nevada state law. I get fed up of auto bidders and so anyone who does not reply with the keyword “donut” in the reply I will assume has not read this project brief. It's an easy one, I just want a little preliminary research before deciding if to pursue further. I want to know please, I engaged an immigration attorney to get me a visa to live and work in the USA. He advised an E-2 visa and I engaged him to do this. The work was performed between May 2017 and February 2018. Is it too long ago to file for malpractice, or to request a refund? There is extensive evidence of this being handled very badly, including 7 attorneys witness statements. So I don’t want you to comment on the viability of the case, just if its too long ago to file. If an attorney sells his Californian practice to another in California, typically are the risks and cases passed on? I have a case with an attorney who had no professional indemnity insurance, and it turns out he made a whole heap of mistakes, to the point where it looks to be a fraud. Because I knew he had no insurance and no assets, I didn’t pursue a claim. Besides, attorneys advised I do not pursue this until getting a visa to come back to the USA. Well, it looks like the damage he has caused is so severe it could be years if at all before I can get a visa. I want to know if it’s likely the company that bought his practice out has insurance that would cover these issues. In England, if an attorney buys a practice it includes buying the risk of malpractice and related lawsuits, and the insurance would cover for that. Does an LLC set up as a partnership require a resident agent? Can the resident agent still be classed as a resident agent in Nevada if he relocates to California? Please can you answer these questions for me, I will then review my position and decide if to take this further. Thanks in advance, Scott.