Here is the wacky thing about freedom of speech.
1. It was designed to protect political/regligous speech. Note that all speech is not protected, your right to freedom of speech ends when you begin to advocate to harm others, when you use obscene speech as designated by the public, or when you advocate the violent overthrow of the government. (there are other reasons i'm sure but I'm not fully awake so will leave it at this).
2. A sign (if it were political in nature) would be protected and "should" not be governed, unfortunately (or fortunately depending on your view) most signs are not considered speech but are thought of as well for lack of a better term construction and or property.
3. One rule for one group and another for another has nothing to do with freedom of speech, it has to do with discrimination. In the case sited above the city has granted leeway to major business's in an attempt to increase cash flow for the town treasury. (Faulty thinking I know, but what can you do) Your clients speech is not being infringed on by the fact that Mc'D's can have a larger sign then he can, however his rights as a property owner are. Yes it's hypocritical, but that is where it then becomes the citizen's job to change his/her representatives to ensure that all are treated fairly and equally.`
hehe, as for the stealth tax, once again we the citizens have let it happen because we do not pay enough attention to what the gvmt. does. Gvmt when left alone will slowly attempt to reduce your rights and increase it's power through taxes, laws, and other means. It is the nature of government to try to become more powerful. It is the duty of the citizen to make sure the government does not become to powerful. It's a constant game played between all governments and the people governed.