Is it possible to view the tax rates of a settlement besides when you first enter the settlement?
Go to your map, default M, and click on the settlement icon for the place you are curious about. Taxes along with town upgrade information, influence, and your storage are all available as info to you on the right side of the screen where it will pop up a tab.
See the tax info on the bottom right next to town upgrades. From top to bottom it is 'Property Tax' 'Trading Tax' 'Crafting Fee' 'Refining Fee'