Where is the derogatory comment about women? Other than what "moviegoer Michelle Williams" said was her opinion?
The possible (probable?) issue I see with this law is that of "where is the line drawn"? Apparently, "sexually explicit" within the law includes BDSM. This application seems to be fairly clear to me. It might be less clear with other movies though.
Booze laws have always been interesting animals to me. Beginning with the advent of "Blue Laws", it has always seemed to me that the loudest people in the State House win when it comes to the where, when and how of alcohol sales and consumption. I'm not sure if this has changed, but I was in NY at a time where carrying any *opened* bottle of liquor in your car anywhere but in the trunk was illegal. That is, if you were going over to a friend's house with a bottle of previously opened alcohol, it had to be in your trunk. At the same time, you can be in New Orleans and go to a drive thru daiquiri stand, and your drink is considered to be in a "closed container" if the straw is still wrapped.
Here in Washington several years ago, there was a change in the law which has allowed businesses of a certain size to sell hard alcohol. (Previously, hard liquor was only sold in state run stores.)
He or she who has the loudest voice (and most money?) tends to win on these things. Now, to get them changed? You need a louder voice.
In terms of this law in Idaho, I don't see it being on the radar of anyone with deep pockets enough to get it changed. Perhaps if the law is enforced to the extent that it majorly impacts the theatres' bottom lines?