Looks great Ross!  For my part, I don’t like the rounded shoulders.  Breaks the continuity of the assembled piece.

I like GF Outdoor Poly for stuff that will set outside.  For Oak I have used a sealcoat of shellac then applied gel stain pretty heavy-handed and let it sink into the grain.  Then remove the shellac with alcohol and it will leave the grain darkened but the faces natural.  Then topcoat.  Definitely experiment on scrap though!