Yes, if you pick your waterproofing carefully. Thompsons has some very good options for different surfaces.
Yes
terpentine should do the trick
Belt sander the fastest way.
No, primer has no lasting qualities as a finish. It needs a harder paint over it.
Spar varnish can be used in this scenario, and would give a great shine to the deck. However, depending on the thickness of the layer of varnish applied, it could rapidly turn cloudy and destroy the look of the cedar. Consider a sealant instead.
From what I've recently been taught was that it rose to almost vertically above the water i.e 90 degrees
Use the thinner of that paint and hope it doesn't affect the stain. There is no other way.
* Orlop deck: The deck or part of a deck where the cables are stowed, usually below the water line. It is the lowest deck in a ship.
That depends very much on the type of wood and the make of stain. I would expect it to last at least 3 years before re-applying.
a bucket.
Yes, there is. Here is some I found while searching.http://www.mtlogfurniture.net/instructions.html
It lasts about 2 years. If the deck is well prepped.
The best deck is what you like and how you use it, there is no best deck just like water puts out fire and so on there is always a meta-deck that will always beat another meta-deck.