The limitations on the use of the clipboard are related to security so I fear that any further "improvement" will simply reduce the possible operations.
What you can do now is to access the clipboard to do cut/copy/paste using an hidden text field but the operation must be started using the standard hotkey (e.g. ctrl-x/ctrl-c/ctrl-v) by the user. The idea is that a program should not be able for example to access the current content of the clipboard unless the user knows this is happening (because s/he typed ctrl-v).