When designing a good Web GUI what expectations can we expect from an end user?

I've come up with the following, but I wonder if there are any others which can suggest..

• If I click on a hyperlink it will take me to another page/part of this page
• If I tick/untick a checkbox it might alter the page state (enable/disable elements)
• If I click on a button I expect it to do something to data.
• If I click on a button I expect something to happen immediately (either to the current page, or for me to be taken to another page)
• If I have clicked on a hyperlink and it has taken me to another page, I expect to be able to use the Back button to get back to the previous page in a state similar to that which I left it in
• If I change something in a form, I can change it back to its previous value if necessary
• Unless I click on the 'Submit' button nothing should happen to my data.
• If I bookmark/favourite a page then it should show the same related data each time I visit it
• If text is underlined and looks like a link, it should be a link and act as one

The reasoning behind this question is more a 'UI from hell' one. For example I have come across pages which checking a tickbox next to a record will delete it, straight away, via ajax. To me that just seems wrong, a checkbox is a toggle - something which a delete operation definitely isn't!