Cut, Copy, and Paste only work with the desk accessories. Use Add/Delete Child to edit the nodes in the tree.
To take a node out of the tree by hand, click on its parent and choose Delete Right (or Left) Child from the Edit menu. To add a node, click on a node with less than two children and choose Add Right (or Left) Child.
However, using the Edit menu you can only delete leaf nodes (nodes with no children). The reason for this is that when you delete a node with children, you leave nothing pointing to those children. They are, so to speak, lost. To remove a node properly, you have to have some formula for dealing with the children--you have to find new parents for them (attach them to other nodes in the tree).
Remove Word has one such method for removing non-leaf nodes. See Explain Alphabetical for a description.
Note that you will not be prevented from making changes that may mess up the tree so that it is no longer a valid alphabetical list or parse tree. In particular, if you insert a node by hand, don't be surprised if Find word or Remove word can't find the word if it's in the wrong place.
