But a truly objective test has clear benchmarks/criteria. You have to be more specific with your time frame to exclude "borderline" cases.
For example, do I have the right to infect cicada pupae with a deadly virus which will kill everyone in your society when they emerge from the ground 17 years later? The effect is not "immediate" by your criteria, so haven't I got the freedom to do this?
I'm sure if I sat down and wrote a treatise on the subject I could better define those details, but, alas, that probably isn't happening tonight. What I posted was a general guiding principle about the theory of social contract. It is a mutually beneficial agreement to restrict some liberties, the restriction of which give greater benefit than cost to all the members of said contract. Ultimately, the benefit everyone gets from others not being able to kill them at random outweighs the cost of not being able to kill others at random. But history has shown that it is too easy to go from this to the protection of a few or one (say the land rights of the king) at the expense of the many (his subjects) or even undermine the rights of a few for the advancement of the majority (civil rights issues). The solution is to minimize the extent of liberty being restricted to only those that are fundamental to the social contract, which would be those liberties that, if not restricted, would without fail undermine the very point of having a social contract in the first place. But to even approach this questoin objectively one cannot allow the masses to theorize about how a certain behaviour or belief will eventually cause the demise of society, for the dangers of this are well documented. So one must restrict the threat to that which is immediate and definite but can also include things that are directly related to such dangers such as conspiracy...but to move to things that may be an indirect threat, like publically advocating the destruction of the social contract is probably going a bit too far.