I spotted one glitch in your listing - it says property type is bed and breakfast - no wonder they expect breakfast to be served. You need to change that to private room. Suggest a nearby cafe for breakfast - that should be a hint.
Since the 4th floor without elevator is an issue - tell them before you accept. This way there will be no surprises. Guests from the far east can sometimes be a challenge and do not fully understand the concept. Personally I only accept them occasionally as they are really demanding and need a lot of follow up and likely to leave funny ratiings. Make sure they understand it is a private home with shared facilities before you accept. It may take some more work initially from your side, but in the end there will be less room for surprises and your ratings will improve.
Is there any way to mark your doorbell with a red dot or other easily spotted marking.
Be very clear in your house rules about the heating/open windows issue.
How do you get your guests to read the listing - keep it as short and as accurate as possible.