I'm not sure what your relationship is like with leaders in your community. So if I'm preaching to the choir I apologize in advance. We don't have too many issues with our town. I feel like our input on sign related rules or laws is appreciated by the powers that be. In fact we are well respected in our community. But that didn't happen automatically. We had to get involved. I'm reminded of the old saying: lead, follow, or get out of the way. In other words if we don't like the decisions the powers that be are making, we make our voices heard and offer up an alternative way of doing things, and that has to be done with a bit of tact and without being divisive. I don't know if I would recommend coming at them with accusations that they are violating your freedom of speech, whether it's true or not. There is most likely a better way to address all this, and if they feel like you are with them and trying to help rather than against them, I think you'll get better results.
I've noticed a bunch of these towns borrow ideas from other towns. Other than the changes we influenced, most of our sign code was borrowed from another town. I think the thing you have to keep in mind is that those ideas may have worked in that other town, or perhaps the other town didn't have a sign person who made his or her self heard, and people that don't have an understanding of our trade made rules that don't work. But the people in your community won't always know if something is wrong unless someone clearly explains why.
That being said sometimes you may also have to learn to choose your battles. At the end of the day the pros of your community and all their rules must out weigh the cons, otherwise why are you still trying to do business there right? The moment the cons outweigh the pros, then you need to decide: Lead (get involved make changes), follow(deal with it), or get out of the way (pack up and move somewhere better).
So my advice is go through the proper channels, as a business person get involved, build some clout. You can choose to see that as a waste of time, but the more you are involved the more influence you have and the easier this stuff will be in the future. Also it's a good way to network. We do a lot of business for our city.