You have to acknowledge them within 24 hours, you don't necesarily have to make a yes/no decision. By pulling your listing out AirBnB ensures that guests continue to use the platform. It's one of those "greater good" things. you can also create a "new" listing and just duplicate your current property. New listings get pushed to the top. Then delete the duplicate once you've accepted a few bookings. You can also use this to offer future guests the option to alter the reservation and switch to your original listings.
I have additional house rules that basically force guests to meet my criteria for my personal trust and safety. They have to message them to me as part of the process so that they cn be held accountable. IF they don't, I have the right to deny them access for failure to follow house rules before they ever set foot on my property.
1. Drop your price below everyone in your area and it'll show up later in the list. You'll probably have to accept someone you wouldn't otherwise accept, but you can set up a maximum stay and set it to 1 day (the options are off to the right in your calendar screen)
2. You probably shouldn't. But it might help you develop your personal thresholds. Every house rule I have is based on an unpleasant experience with prior guests.