You should look at what the operating agreement says about removing managers.

Is there a law to help protect “at-will” employees from harassment and abusive treatments from their employers?

Unless you were abused or harassed based on a protected characteristic, such as race, gender, religion, disability, etc, it would not be unlawful.

Can a company knowingly hire someone with a suspended license, then use that as a reason for termination?

Assuming you are an at-will employee, yes, your employer can do this.

Suing someone with no address

You can sue them regardless, but in order to serve them, you will need to hire a private investigator or use some other method to find out where...

I was recently fired for having "multiple complaints from every department" about my bad attitude without warning

Assuming you are an at-will employee, this would not be an unlawful termination.

Database for civil actions by party name?

You can try searching the websites of each of the County courts in CA. For example, LA County Superior Court lets you search by party name.

Can a company transfer you to a different property (same owner/ sister property) without your consent?

Assuming that you are an at-will employee, yes, your employer can do this.

Company won't let me cancel without signing a bogus stipulation in their contract?

The answer to your question would depend on what the contract you signed up with stated.

I got hurt playn softball can i get paid for it?

It depends. Sometimes waivers like this can be gotten around. A full consultation would be necessary to properly advise you.

Question regarding Nevada corporations and the IRS

Legally speaking, based on what you posted, the corporation should be registered as a foreign corporation in California.