No, it's not a hack against the 1st amendment. Any private party action is constrained by the 1ST amendment. It's a well resolved question.
The unanswered question is what the limits are to out of state state power? It's a billion dollar question.
Private lawsuits can seek relief that otherwise would be beyond the state's power under the 1st Amendment. For example, speech itself can be penalized by a court if it violates a non-disclosure agreement.
Not really. It's an artifact of contract law.
Could you give an example that is not a byproduct of a contractual provision?
Cool, I'm sick and tired of Christians forcing their beliefs on me. I'm sure that if a law were passed allowing me to take private action and sue people for being Christian that would be fine since it's not the government taking action on religion?