Hi,
1. I would recommend to set the "registration" setting to "guest" in the Checkout tab of the HikaShop configuration. That way, users will have to enter their email address and address each time they checkout.
2. You can remove the "shipping" and "payment" view from the "checkout workflow" setting of the HikaShop configuration if you don't want shipping/payment on your checkout
3. You can create custom fields of the table "order" via the menu Display>Custom fields if you want to ask questions to your customers during the checkout.
4. You can edit your currency via the menu System>Currencies if you want to change the display settings of prices with that currency.
PS: please open different threads for different questions so that it is easier to follow for everyone.