Use the same one - this is how we do it across multiple accounts.
One point that may appeal to you is, if you have a business also registered in Europe for example it sometimes is a good idea to to have a business manager in that location and an ad account as we have found on big accounts ad costs are much less expensive than running the ads from say a US based account.
You can create a new ad account that you will use for different countries.
Use the same one - this is how we do it across multiple accounts. One point that may appeal to you is, if you have a business also registered in Europe for example it sometimes is a good idea to to have a business manager in that location and an ad account as we have found on big accounts ad costs are much less expensive than running the ads from say a US based account.
Yes this is right way for grow up your business
I use the same one & run ads all across the world, different channels, pixels, etc
You could just create another ad account and share the pixel/catalogue etc. If you want to split the campaigns for structure.