Is a Lawsuit considered a "Threat" or "Extortion"?

The statement that one intends to sue is surely a threat, but I have never seen any case suggesting that it is extortion, provided that the basis for the threatened litigation is sound. If one makes such a threat without basis, it could be problematic, but so long as there is a basis for the threat, you should be ok. As an added protection, you might indicate that the "threat" of litigation is made only in the context of sharing information in an effort to compromise a claim. Such settlement discussions often contain the "threat" of litigation if the matter is not resolved.

No a mere threat of suit without more is not actionable. Besides, you could always care out the threat and actually file the lawsuit.

First off it is best not to make an empty statement, but if you have good faith grounds to believe that you may, it is not usually actionable. A civil RICO suit is not a criminal action although it may be related to criminal activity. However, here in California it is not allowed to use the threat of criminal prosecution as a lever to obtain an advantage in a civil manner. I don't know if the law is similar in Nevada.

I litigated this very issue and the Court found that if the party is following through with a legal right the party has then it is not extortion. For example - if Joe tells Bob I'm going sue you unless you pay me the money you owe under our loan agreement - not extortion. However, if Joe tells Bob, I'm going to break your legs unless you pay me the money you owe me - more like extortion. Finally, if Joe tells Bob, I'm going to tell the cops you molested the neighbor unless you pay me $5,000 - extortion. Of course, if you're considering filing a civil RICO claim you should contact an attorney.