Welcome candomain! Nice to have you here!
Personally from my experience I think you should leave the method of payment to be decided between the two parties. All of my large sales have been completed in USD to avoid agreeing on the conversion rate and since escrow.com does not offer to complete transaction in CAD.
I’ve never had a buyer not complete transaction because it was not in CAD funds. Once they know you’re completing through escrow they don’t care.
Also, there has been a lot of news released in the recent year regarding interac etransfers and the high chance of fraud. There has been many scenarios where the person sends an EMT and once they determine it’s fraud the money gets reversed. The major banks have put notices that you should only use email money transfers with family and close friends. Never with people you don’t know. For me, it’s not worth the risk. But to each their own.
Yes, I feel listed prices should be in CAD for consistency, but settle it however the parties decide. I've done a lot of sales and never once had a complaint about a currency exchange rate.
Regarding EMT, its like any other non-escrow sale, you're always taking some level of risk. I use EMT or EFT all the time, but I'm also always sure I know who the buyer is. I find people may try and negotiation anonymously, which I understand, but when a price is agreed to and it comes time to execute, then I expect full transparency for invoicing & taxation purposes. If the buyer is still acting shady at that point, then its Escrow for sure.