Does it matter whether I press Tab or several spaces when I want to move text to the right?
In some cases, pressing Tab and the Spacebar several times seem to produce the same visual results, but you should reserve pressing Tab for those times when you want to indent or align several lines of text. You can more easily adjust tab spacing later if you want to change the indention.
How can I remove items from the Office Clipboard Task Pane?
Either click Clear All to erase the entire clipboard or right-click over the Clipboard Task Pane item that you want to remove and select Delete. Remember that if you've hidden the Clipboard Task Pane, you need to select Edit, Office Clipboard to display the Office Clipboard Task Pane once again.