Shellac is hard to beat. It seals against moisture very well, dries in a few minutes, even over wet wood, and is a thin coat that can be easily scraped or sanded away.
I wouldn't use any type of oil to try to seal wet wood, or bow wood that I want no penetration on.
In your plan... in Item #1, I would seal ALL ends and backs, with shellac, even if I planned to make a bow with one of them the very next morning.