Stuff can absolutly be deleted. If you overwrite the stuff that was previously saved there it’s gone. The point is that cloud providers often just don’t delete your stuff. And whatever you do your network provider allways knows what you search for.
Student dorm. I don’t think they are actually making a lot of money of me, but it’s simple advertising.
300mbit for 17€ a month in germany
It all depends on your tiredness and blood alcohol level.
Oh most social media probably keeps a copy. But your search history is usually stored locally, so it’s possible to delete that. Your internet provider only has a history of all sites that where visited via your internet connection and is unable to backtrack something to a specific device.