I'm looking for any advice- should I try Furnished Finder for just a 60-day window? 

They should also budget a fair amount of money to furnish and for reserves.  

Maybe your stay is better (newer, better furnished, more amenities, etc) or worse - so you can adjust your expectations accordingly. 

If the occupancy is good, a. you and grandma sign a lease option agreementb. you stop eating at Mc Donalds c. you use that money to clean up and furnish the Studio3.

If you have an off-peak season, you may also want to consider a mid-term rental site like Furnished Finder.

Not sure about furnishings.

If your boss came over to your house for any reason, asking him not to light up inside is pretty well accepted, asking him to take his shoes off, well, I can't imagine asking that of your boss nor what kind of nut he might think he hired.A little etiquette, I realize that Cali is known for having nuts out there, but it is considered bad manners to ask guests to take off their shoes, I know because it was on the Today show yesterday (LOL) so the host is to furnish them little booties to wear over their shoes or provide slippers/foot wear.

I had a remote new construction STR going on and had documented the hours spent working the cleaning, continuing to add to the furnishing and landscaping of the STR.It was 1:45 drive each way so there was a lot of miles, hours and expenses. 

My main issue is, that I would like to rent a unit as a furnished monthly rental meaning a minimum of 30 nights- most guests are looking to stay 3-6 months.

Then, I cross check Airbnb + VRBO and check rent rates for comparable properties within relevant proximity, and I mentally slide the scale, depending on features, views (in our area, red rock views), location, construction quality, other finishes, quality of furnishings, etc.