-mayors should fund the public and legal departments
-remove ammunations return the crafting, higher the weapons parts prices.
I suggest to make /sponsor available for mayors only and under specific conditions, like minimum 30 people online.
Ammunations shouldn't be removed, but as you offered they should sell weapons only to people with licenses. And in order to get a license one player should state a reason to own one, which on other hand will improve the roleplay.
If the above is implemented, selling weapons outside ammunation will be script-wise illegal. Crafting should return, but limited people should be allowed to, because weaponry business isn't that accessible for average people, you know. For example the leaders of the recognized/official criminal families should be allowed to craft weapons.