When I start to post, I don't see "furnished" anywhere as an option for listings.

Other than Regus there are very few options. 

You can do a trial and see if bank feeds connect, if it does, I would then recommend using it over QBO.One of my client that just started in development is short on funds so Xero was the only best option and they are using a local bank so we couldn't connect and a lot of manual entries. 

There are a few other options as well that can be taken to escape the FHA to Conv. 12 month rule.

That would be best option as a traditional bank wouldn’t do this I read that I can assume the existing mortgage.

Also, when they said they have "network" to find investers/property owner to land my offers, and "system" to calculate profits in order to show whoever owns the property short term rental is the more profitable option.

I would first check to see if HELOC is even an option - in TX its hard to find and can only be done for a primary residence.

But there are options for interest only first five years. 

As for my Airbnb research, I have spoken with a person who runs numerous Airbnb’s in a different area (city atmosphere) who provided good ideas on how to smoothly run the property.

I used to do contractor work and we would always inform the customer of their options.