I have a couple of suggestions for improved usability in EPiServer's admin mode. Administrators and developers are also users who need to save time and want to avoid making errors.
1. Confirm dialogs whenever the user can delete or change something that can't easily be undone, like when removing properties or page types. It is just a bit too easy to accidentally press the wrong button when "Save" is right next to "Delete".
2. Greater flexibility for changing the order of the properties on a specific page type. Maybe using drag-and-drop could be possible? Or to be able to manually type a sort index. Moving properties up and down can be very time consuming when the system is a bit slow!