There are exceptions, but I would needs high degree of confidence that the unit is the exception before spending money to furnish.I will add that my long time STRs that have done great are only doing ok this year.  

Cornhole board games, Horse shoes, Volley Ball net or Basketball net, Non expensive poker table with cars and chips, board games, Playstation or Nintendo for the teens, even spend a little extra for a full size stand up arcade game.You would be surprised the extra stars and kind words a few family nights of fun can make memories and people wanting to come back!

Seems you will spend your liquidity on one property with the info you’ve shared.

One other side note, I do 4 of these in our 8-unit apartment building so that increase in NOI also increases the building value more than I spend on the furnishings (e.g. $4,800 increase in NOI at an 8% cap rate increases the building value by $60,000).

For us we either do or do not provide and if it’s provided then we as the owner are responsible for routine maintenance on the appliance and only time tenant is responsible is if they did not take proper care (or use) of the appliance.as a sidenote what if a tenant said - cool not part of lease come remove it I want my own fridge - you will spend more moving it out than you would by including it in lease. 

Not sure if thats the case in Denver, but might be likely based on what I've seen when spending time there (not that much lol)If you move into mulit family, you will get a homeowners policy

I’m a real estate pro so material participation isn’t an issue, but the majority of my clients are in the $300k-$900k/yr gross household income range and so using STRs is not only the best way to get great ROI on real estate nowadays but the tax benefits are the primary driver for most including myself.  

I would also spend money on a professional photographer.

Suggest you either spend more time leaning about real estate investing or find a relative or friend to invest their money with you.

First, have a conversation with an accounting firm to see if a cost segregation study will be beneficial to you.You don't want to spend money on something where you won't get a benefit from.