Damage to furnishings and other belongings is always a possibility in an MTR, just as it is in an STR. Your deposit should be enough to cover most common damage. It usually comes down to the type of renter you get. I find families with children or groups of adults staying at my STR do more damage whether intentionally or accidentally than my longer stay midterm guests. I don't have specific language in my lease regarding damage to furniture, but damaged furnishings are mentioned as a reason to not receive a full security deposit refund.
As for cleaning supplies, I equip the property with a full set of cleaning supplies: vacuum, broom, mop, toilet cleaning brush, scrubbing sponges, and full containers of multi-surface cleaner, floor cleaner, Soft Scrub, and toilet bowl cleaner. I provide a small pack of dishwasher detergent and a small bottle of dish soap. I find the supplies usually get used and, to me, that's money well spent if my guest is keeping the property clean. For paper products I provide 2 rolls of paper towels, a small roll of trash bags, and a 4-pack of toilet paper. You can find a happy medium between being stingy with products and spending a fortune.