AFAICS, you propose to replace the term "clipboard" by "text". I don't see what we gain this way. People using the selection mechanism may even be confused.
If there is no selection-related items in the menu, every paste is then paste clipboard so there is no confusion. You see: Paste (from clipboard) Paste special (from clipboard and selection?) Paste special, Clipboard as lines (what does the first paste do, as lines or as paragraph?) So: Paste (from clipboard) Paste special (from clipboard) Paste special, Plain text as lines (from clipboard) is clearer. Bo