Oil ? Finish on Ash Guitar Body

At long last I am about to complete the "woodwork" part of my guitar.

I am using Ash for the body with a rock maple neck,rosewood fretboard.

I am going to use Feast Watson Tung oil on both (and lemon oil on the fretboard) BUT I am not sure if I should use a sanding sealer more so on the ash as it does have a fairly open grain.

Does the Sanding Sealer ,seal the grain?

If any body (excuse the pun) has any advise.I am looking at getting a smooth ,natural finish with a slight sheen.

What effect would the sealer have on the tone quality of the ash?

Should I buff the final cote?

How do I post a photo?

TIA

Greg