DC2 Tax rate configuration
Answer to second question is that the tax cannot be calculated until Billing address is present (as depends on 'territory' of store &amp; user) - so tax line is not seen initially until user reaches review stage.  Once the tax (as an 'adjustment') is added to order, it then stays visible - eg if user goes back to cart to add/remove items. The tax value then gets updated to reflect new cart contents on clicking 'Update cart', or clicking Checkout.