Whoa. I assume they are out by now? I would have kicked them out (or at least contacted Airbnb) the moment I saw my earrings on the guest. That is unsanitary, not to mention weird. Did she steal them? Did you ask her about it?
Internet service sort of sounds like something you should deal with on your end, even though it's usually fine. I can't imagine what they would do wrong to knock out internet service.
Re shampoos and stuff, were they stored away? How many little shampoo bottles are we talking about? You might have to just chalk that up to the cost of doing business. Only leave stuff out -- anything, like food, soap, etc -- that you don't mind losing. I've heard of guests just straight up emptying a tin of teabags into their purse. Oh well. Weird but not a huge deal.
Did you talk to them about the early arrival? Or will this be the first they've heard about it?
Open up a case in the resolution center. Charge for the extra day and cite your check in time. Also charge for the earrings.
And please let us know what happens.