@Jane556 The text I put in quotes was just a sort of example I made up on the spot of how brief you can be in a review and still get the salient points across. Sometimes hosts are so upset about bad guests they write some long rant, mentioning every transgression in detail, which isn't needed and can just make the host look a bit off or hypercritical. What I was suggesting is that after you compose the review, you could post it here on the Hosting forum (or the Host Circle forum, which guests don't have access to) if you'd like other host's feedback on whether they think there's things you should say differently or leave out. Many hosts do that if they're unsure about how to word a bad review.
I'm not sure what you mean "can a prospective host contact me about them?" Like, could another host read the review when considering the guest's booking request and contact you for further details? Yes, they could and occasionally do, but I don't think that happens very often- other hosts will just read the review and and think "Thanks for saving me from a horrible experience, Jane" and hit Decline. And if you give a 3* review or less and "not recommend", the guest won't be able to Instant Book- they'll have to send a Booking Request to all hosts in the future.
Yes, it's one of the better policies of Airbnb that reviews are blind. Neither party can see the other's until they both submit a review or until 14 days have passed if only one party submits one.
No, removing trash isn't required by Airbnb (there's some wording about leaving the place as you found it, but that doesn't mean much to a lot of guests)- each host has to be explicit in what they expect the guests to do. Some hosts want the guests to strip the bed and start a load of wash, and fill the dishwasher and start it up before they leave, some hosts just expect the place to be left in good condition with personal messes cleaned up and don't expect the guests to do anything more. As long as you're clear in your listing rules and reiterate with guests when they book and arrive, it's up to you. Things we would would consider common courtesy that need not be mentioned, like not leaving piles of trash in the place, unfortunately need to be spelled out for some people.
If I were you, I would not leave your personal boxed or suitcased things anywhere a guest can access them. I'd lock them in an "off-limits" closet or garage or store them at a friend's place.
I'm glad you've had lovely guests in the past. I get great guests as well, but a bad apple could always slip through.