well, I can't get the multi-right But, what Bear Foot said. 1 - In many states fireworks are illegal. 2. Not all dogs are going to be bothered by the sound of fireworks while others will be terrified. 3. shooting/throwing fireworks at the dog is going to get you an animal cruelty charge if you injure the dog.
If the dog is on your property repeatedly and you have it taken to AC, you aren't going to be charged with stealing. Now, if they were able to prove that you removed the dogs ID and THEN took them in and lied about not knowing who they belong to? Then maybe the owner could take you to small claims court, but even that would be iffy. In my opinion, lying never solved any problems so I avoid it. And removing the dogs ID and saying you don't know who they belong to is stupid since taking them to the pound is perfectly within your rights. Give the woman's name and phone # to AC when you drop them off and let them call her to come get the dogs.
I would also talk to my local sheriff. Tell them the situation and ask them to please inform the woman of the consequences of her dogs running loose (legal to shoot them) and hopefully that will get her attention.