Nick here from Shopify.
Really good question. Yes, you are correct, if your online store is set up as if it was from the USA, then you would succumb to the taxes as if you were there. How you deliver your products after the fact is up to you as a business and it will not impact your costs. We always advise to reach out and talk to your local tax office or a professional account about getting set up with your taxes though as we are not tax experts. Shopify does, however, have a helpful document on all things taxes when setting up taxes from the USA which you can see here.
Don't hesitate to ask should you have any other questions!
All the best, Nick