I'm a newbie. I traced a photo with live trace, it looked good. Then I expanded it, and I can't get these paths to fill or take a stroke width, whether its grouped or not. I drew a rectangle and it looks good and shows a fill and stroke width.
Based on your layers panel in your screenshot it looks like you might have accidentally converted your shape to guides. Your layer icon is showing a blue box and typically it will preview the whole shape contained in that layer which would include your custom shape.
Guides are ignored in an icon preview. So I highly believe your shape is no longer an official "shape".
To undo this select your guide. If you can't View > Guides > Uncheck Lock Guides Then Select the gude and View > Guides > Release Guide