Sounds like you’d need to have your payout bank account be a US bank account (or set up to be in USD) for the conversion fee to not apply. If you’re only selling in the US or the bulk of your sales are in the US it would definitely save you some money to switch to a USD bank account (assuming that account doesn’t have some crazy fees or anything). For the CC you might want to just get a US credit card as well. Keep it all in the same currency till you need to use it in Canada?