If guests are routinely complaining that your futon is not what they were expecting, perhaps the best thing to do is to just figure out what kind of solution the guests want and replace the futon. My AirBnB currently has two double beds and four wooden folding chairs. After it is remodeled it is going to have one queen-size bed and one full or queen size sofa-bed. I am not saying that is what YOUR guests want, but I think/hope it is what mine want. so they have a comfortable place to sit and if there are four people they also have a somewhat comfortable place to sleep
I guess I have been lucky I have not had anything like a hair dryer taken. I *might* have lost a pillowcase and towel but I am not sure because I noticed them missing when I was returning the clean ones to the AirBnB property.
Personally, I think the answer is risk management. If you have to replace a hair dryer, I'd buy the cheapest one you could find or even a used one. like this one: https://www.amazon.com/Conair-1875-Watt-Dryer-White/dp/B001LQY1X4/ I replaced the clock radio in my AirBnB (the radio did not work when I acquired the property) and I bought a 'used' one from Amazon. It was a discontinued Best Buy private label model and still had the cellophane on the face so it was sold as used so it was non-returnable but it had never been powered on.
As a trivial aside someone who apparently does not know that correlation does NOT equal causation, hypotheses that you can earn $10 more per night by proving a hair dryer 🙂 https://qz.com/810309/you-can-earn-10-more-per-night-on-airbnb-just-by-having-a-hair-dryer/
As far as consumables like shampoo and toilet paper, I just buy travel size containers from Walmart, they are a $1 each and toilet paper in bulk. I specify in my listing that guests get one travel-size container of each and one roll of each paper product. If there is a partial roll in the rental, I add one roll, so every guest has at lease one full roll. I also state that there is a convenience store on site and that I will not replenish consumables during the guest's stay. I must be doing something right since I have an overall 4.7 rating. The reason it is not higher is the unit is due for renovation, something that is going to happen later this year.