This is getting to be surreal in its utter stupidity. You might want to look up “non-sequitur”.
Beagle, if I understand your argument correctly you stated first that the French law is unacceptably vague, then went off in a discussion on the existence of vague terms in U.S. law. This is not going to help in any way: you are clearly very familiar with U.S. law hence to you these terms are quite clear. However, that does not make you competent to decide whether for French citizens and French lawyers the proposed terms are sufficiently clear.
It is possible that the specific words have received a precise definition in substantial case French law. An example of this happening is the ‘public order’ exception in several articles of the Rome Treaty on Human Rights: this is an awfully vague exception, but hasn’t led to frightful abuse of state power. There is some consensus on the meaning of such a term. You cannot make an informed judgement about this proposed law if you are not familiar with the legal system in which this proposed law would function.
That said, it does appear that the wording is vague even for French citizens and lawyers. But only a French lawyer can tell. (clairobscur, où est-ce-que vous?)
With respect to not going to France: by the same reasoning European subjects shouldn’t go to the U.S. without reading up on the Patriot Act and all relevant the case law with respect to criminal and tort law. If you don’t like France, by all means stay at home. Your argument, however, doesn’t provide sufficient reason.
The “corrupting the morals” part, of course. “Of a minor” is clear enough, but how is a person supposed to know exactly what constitutes “corrupting the morals”?
You said earlier that it meant encouraging someone to commit a crime, and I pointed out an act that has nothing to do with encouraging anyone to commit a crime, yet was still counted as “corrupting the morals”. That’s just as vague as “offending the dignity”.
Do you have a cite for the claim that “immoral purposes” means “illegal purposes”? Seems to me that the Mann Act prohibited transporting women across state lines for “immoral purposes”, even when such purposes were legal.