And you are lucky, because I just finished my Constitutional Law 2 class, and I actually remember some of it.
You are talking about a freedom of speech issue, and you are being regulated in a TPM (time, manner, place) kind of way. Generally, TPM regulations are constitutional, provided that the government's interest is "substantially" related to the good they are trying to promote (or the evil they are trying to protect against).
In your case, the city can legally and constitutionally limit your protest activities to the time, manner and place of your protest. They have to allow you some access to voice your concerns, and especially if you adhere to the "time honored" methods of communication (i.e., standing on a soap box, handing out leaflets, just talking to people but not harassing them, etc), then you are OK.
So remember, if you are going to do your protest, obtain all the necessary permits from the city and the local police, and follow the instructions (directives) in those permits to the letter. It appears you have done/ are doing this. If so, then you should be OK, that's my guess. That doesn't mean you won't get arrested, but even if you do, it will be thrown out eventually, even if on appeal.
But your real question is, can a lawyer enforce the provisions of the city and police permits? And the answer is, emphatically NO. The lawyer is not an officer of the city (an administrative and executive function), the lawyer is an officer of the court (a judicial function). So, tell that asshole lawyer to blow off (no threats, but general profanity OK), go back to law school, and reread the text about our tri-partite style of government, and the separation of powers.
OK, that's my suggestion in response to your question.
However, I think it was Doc who made some relevant suggestions about the propriety of this type of behavior, especially in the great state of TX. I'll be honest with you. My father has lived in Houston area since 1974. I have been there a number of times, but I try to avoid it. Nonetheless, I will gladly admit that Texans are about the superficially friendliest group of people in America, at least that I have met. On the other hand, (and no offense to the various Texans on this board who prove my opinion wrong), I find that as a rule, Texans are about as dumb as a stump. Once again, my apologies to the handful of Texans on this board who clearly are the exception to my superficial, biased, and general rule.
In other words, don't count on the state of TX to get it right (and you know that from your personal experience, don't ya?).
I didn't like TX when I was living in MI, and I like it even less now that I have been living in CA for 25 years. We hate them, they hate us. We know we are right, even if their man is in the White House now. LOL.
Good Luck.