Most important is lot size, and basement  ceiling height.  

Is the house hack strategy off the table? 

You'll most likely find your staffing costs to be in the neighborhood of $1,200 to $1,900 per unit per year, depending on property size, class, and market. 

That will require a rough and final inspection. 2) When installing drywall you will need a nail/screw pattern inspection. 3) You will need to provide 'conditioned air' to these rooms..how are you going to do this and that will require inspection.Will you have to increase the size of the electrical panel?

I ended up buying a SFH home on a nice-sized lot and I am building an ADU on the property.

But based on that area and depending on the size of your cabin, you may not be as far off on your price as people here think - even with your lower revenue numbers (assuming you didn't accidentally give us net instead of gross revenue). 

I have thought about reaching out to cash buyers who have a decent sized portfolio about possibly managing their STR/MTR homes.

I have an opportunity to purchase a 2019 built 6 bed/6 bath 3300 sqft (Pool/spa, media room, full size garage) fully furnished STR in Encore Reunion community @ 180 per sqft costs me 600k.

I see this home and what you paid and while it's not at all a bad price, I've seen investors offering that size in Palm Bay for as much as $15-25k lower.

This is not a once size fits all question IMO.