Its been awhile since I posted.
The law is not as intuitive or simple as people often make it out to be. Simply reading the text of the constitution is not dispositive of its scope or meaning.
A good example is the Fourth Amendment which reads:
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
While the text of the amendment doesn't require a warrant to conduct a search the Supreme Court has said that a search without a warrant is per se unreasonable. This is subject to many exceptions good faith, automobile, plain view, etc...
In his concurrence in California v. Acevedo, Scalia said the following:
Even before today's decision, the "warrant requirement" had become so riddled with exceptions that it was basically unrecognizable. In 1985, one commentator cataloged nearly 20 such exceptions, including "searches incident to arrest . . . automobile searches . . . border searches . . . administrative searches of regulated businesses . . . exigent circumstances . . . search[es] incident to nonarrest when there is probable cause to arrest . . . boat boarding for document checks . . . welfare searches . . . inventory searches . . . airport searches . . . school search[es]. . . .
If you read Scalia's concurrence in Acevedo, he is clearly frustrated with the court declaring a "general requirement" for a warrant and at the same time littering it with so many exceptions that it becomes a useless rule. He would simply go back to using a test of reasonableness to determine whether a warrantless search was permissible. But he was unsuccessful in ever getting a majority to join him in that.
That is not all that intuitive or simple.
The 14th amendment due process clause is no different. The "substantive due process" doctrine is not at all intuitive or simple.
We pay Judges to sort out these questions and they do.
The 5th amendment takings clause is no different. While I am a lawyer I am not an expert in this very complicated area of law. I only have a cursory understanding of it. A brief westlaw search seems to indicate that establishing a regulatory taking is difficult.
In any suit challenging the California law it would certainly be worth researching and may be worth making as one of the claims in addition to Second Amendment claims.