I personally know both @Jaclyn Cano and @Wale Lawal and can confidently say both are great and VERY Investor friendly!

In your experience what are some ways I can understand the intent of the person who said they're interested in buying? 

Still can be very beneficial for a new investor but personally I think not as good as a service as they had with their exclusive listings where they had inspections already done, rent rolls available, and you can complete the entire offer/acceptance via their platform rather than being handed off to an agent. 

I can see how an application fee per person can be a deterrent for applicants in my case whether for more upscale rentals people may see it as more normal.I am starting off as a non-refundable fee and measure the resistance, then adjust if needed.

This is one of the best personal finance calculators I have seen. https://docs.google.com/spreadsheets/d/1oC4gdK5gXIPjyEFTgo3g...

I'm going to reiterate what's already been mentioned above, but I'm going to actually give you examples of why it's relevant to you to find a U.S. tax professional.1 - You're going to need to file U.S. taxes once you have property down here, there's federal filings, state filings, and sometimes local filings too2 - Tons of tax treaties between the U.S. and Canada that are easy to miss and can cost you a lot of money (important one with rentals - effectively connected income - if the professional you talk to doesn't know what this is, run away)3 - The amount of days you spend in the U.S. needs to be tracked and if you go over a threshold, all of your worldwide income could be taxable by the U.S.4 - Selling real property means up to 15% of your sales proceeds might not be available to you for years (FIRPTA)5 - Lots of nuance at the state and local levels, which both want to take as much money from you as possibleMain takeaway here is that you should find a U.S. based tax person.

I've been informed that completing the course alone may not be sufficient to pass the exam, so I’m seeking advice on how to prepare effectively once I complete it.Currently, my only other resources include a YouTube video, five practice exams, and a textbook.If you have any additional suggestions—whether online or in-person, paid or free—that could help me effectively prepare for the exam, I would greatly appreciate them.

This could give you the cash you need for the purchase and also eliminate your personal guarantee for the loans.

If you've never done it and never looked at properties anywhere in person, how will you know what any of the numbers even mean? 

Personally (as a STR-focused REALTOR), I would never give you numbers and tell you you can hit them.