Good morning. 
It would be nice were the Ctrl+Shift+(oh) keyword window to remember is sizing and Windows location from one session to the next. (This tends to be a not unusual request of mine for such floaters.)
Re Inspector/Referencing another project’s document, I can open an RTF in (eg) WordPad or its file location via the right-click context menu. ‘Nice’, 8) . (Particularly coupled with Windows’ Preview Pane; and with the usual warning about changing its text.)
Could a third option be to open that doc’s project?
Beyond the usual caveat about the user’s manipulation of the document’s location and name, my curiosity asks, “Can the file system’s ‘###’ name get changed due Scrivener’s organizational manipulations?”