There is a tremendous difference between a law that bans snakes over 2', and one that bans large constrictors, venomous snakes, crocodilians, and large lizards. The former is completely ridiculous and has no logically bearing on public safety, the main (or perhaps only) legitimate reason for prohibiting animals at a municipal level.
I agree that a 'test', permit, authorization, etc. would be the best way to go. However, I have yet to see a municipality go this way. They are afraid of the cost and workload of administering such a system. I have come to believe that the only way a system like this would work is at the provincial level.
Even a permit system would be a prohibition, except for permit holders. Prohibition with specific exemptions can accomplish close to the same thing, provided the exemptions are appropriate. It doesn't sound like they are in this case at this point, and I would focus my lobbying at making them more useful. I'd still like to see the actual wording of the by-law, though.
I, too, own large constrictors, all of which have come from previous owners who couldn't care for them. We use them in most of our educational programs, and try to discourage people from buying them very strongly. I am not opposed to the prohibition of them (as stated, I wouldn't include boa constrictors in this) as pets; in fact, I think it is a fine idea.
While the domino theory of municipal by-laws may be true (once one bans, they all ban), I don't subsribe to the belief that once they ban one thing, it will lead to more, and eventually to a complete ban. Reasonable, practical, and enforceable laws tend to become pretty stable and endure without much revision. Unfortunately, even unreasonable ones can endure far too long!
I agree that "we as herpers need to stick together". We need to be organized, and we need to be active in the battle to avoid unnecessary regulations and prohibitions. However, we also need to realize that not all regulations or prohibitions are unnecessary. We live in a society with other people, and we make laws to try to enable us all to live safely and in peace. Venomous snakes, large constrictors, crocodilians, and even large lizards, can and do constitute threats to public safety, and therefore regulations concerning them are not likely to go away. I'd just like to see them be sensible and manageable.