Emails are not in views. You can personalize emails via the System->Emails menu if you use the business version of hikashop.
Otherwise, you can find the email files in the folder components/com_hikashop/mail. You can make a copy and add to the name .modified just before .php so that you can modify that copy and you won't loose your changes when you update.
VAT is not that easy. In the USA, some states have VAT which apply depending on the state where the shop is and where the customer is living. So disabling VAT just based on the currency is not possible.