staining/sealing cedar fence

Yes, but slowly depending on the quality and origins of the cedar.

Like any stained wood. Out of place in older neighborhoods. If you live in a new tract home where you can still see over the tops of newy planted trees, then stain it. As years pass, the trees will grow, you will be annoyed at the maintainance needed by the fence and after a few years of neglecting the clean and stain routine it will age gracefully to a charming gray more consonant with the maturity of the locale. It's your call. HTH

Joe