(a) Yes. (b) No.
Some jurisdictions have special taxes only on fireworks. A quick search shows that, in the United States, Pennsylvania, Michigan, South Dakota, Iowa are examples. In Canada, I could not find any taxes as there are lots of bans on fireworks in various municipalities.
However, I can tell you from experience that is how cross border shopping became so popular. One municipality bans an item and people simply drive to another municipality or order it online.
Enjoy your fireworks!