#3 is allowed by DCM. Besides #2 and #6, all of those other features could probably be layered onto DCM with FastScripts (free for up to 10 global hotkeys, http://www.red-sweater.com/fastscripts/) and some trivial little AppleScripts, certainly nothing that couldn't be done in half an hour by anybody reading this site.
I think $5.50 is overkill for a system utility with some trivial extra shortcuts and visual enhancements.
EDIT: re #3, you can change the magnification of the loupe, not its literal size on the screen.