Most people i hosted are respectful of the fact that they are guests and they are renting just a room, but sometimes i get guests like you had.
I have a limited use of kitchen which is described very detailed in the rules section. What buggles my mind is how people just assume that they can do whatever they want in someones house and dont read the rules. I just had a young couple from Argentina who went in a very early morning 6:45 to the kitchen and started making coffee, some complicated gourmet breakfast and woke up the whole house with 3 other guests and us. My fault though, usually i repeat my rules when they check in, but it was very hectic here before New Year and i skipped that part.
But when i stopped her that morning, and referred her to my my kitchen rules, next day she started cooking some complicated lunch that took her more than an hour and she fried, which is not allowed, as i allow only boiling.
After i stopped her twice within the next 2 days and again reffered her to my rules, i asked them to leave. I told them that their behavoir is totally disrespectful to me as they continiously do whatever they want to do and ignore me time after time. They appologized and stopped cooking, they had nowhere to go as it was New Years, and prices went through the roof.
But.. they hang out in a kitchen, talking on their cell phones loudly, my husband had to stop them repeatedly and asked them to go outside or to their room. They opened windows after i specifically asked them if windows are closed and if i can turn on AC. It was just one thing after another with this couple. WHen they left i sighed with relief.
I would advice to to go over the privacy issue, and how you need it when you are home, and how you need the use of the house. Write and tell them in person how they can not "explore" and go to downstairs, about opening windows, etc.
I have a young couple staying now, longer term. Very sweet, and very respectful. But, there is not taking shoes issue. Every single day i stopped them from going upstairs with their shoes on. He told me yesterday that this is new to him, to take his shoes off, and he is trying to get used to the idea.
Most important , do not be afraid to tell what you think should be told. In corteous, calm manner but say things they need to hear. Most times it works. Many times people do not even realize that they are doing something wrong. With some , doesn t matter what and how many times you tell them, they will still find something to do wrong.