When editing a case or wiki article, allow the author to manipulate the position and indentation of a list item by holding the ALT key and pressing the arrow keys. This should emulate the functionality available in MS Word.
When the cursor is on a list item:
ALT+ARROW UP/DOWN should move the item up or down in the list, respectively
ALT+ARROW LEFT/RIGHT should decrease or increase the indentation level, respectively
If multiple items are highlighted by the cursor, they should move as a group.
An item's contents should not be broken apart if the item is only partially highlighted - highlighting any part of an item constitutes having the entire item selected.
Are the ALT+ARROW KEY keyboard shortcuts you're talking about an option in MS Word somewhere? I'm using Word 2010 and none of those shortcuts appear to be enabled by default.
The good news is that in the wiki you can already get the increase/decrease indentation level functionality (including when multiple items are selected or even partially selected), by using TAB (increase indentation) and SHIFT+TAB (decrease indentation) keyboard shortcuts.
Unfortunately, because TAB and SHIFT+TAB are used to navigate between input fields when editing a case, these shortcuts do not currently work in the rich text case editor.