I haven't tried to fit the oil defense pipe backwards, I just carefully install it the right way around. I agree the offset connecting rod installs so that you put the cap on from the left side.
You didn't say anything about seating the gudgeon pin circlips. I find it needs careful attention. I put them in by gripping the tang on the end of the circlip (in projects radially inward) in long-nose pliers, with the tang pointing upward and the round part extending to the left from the tang. Then I place the part of the circlip closest to the tang in the groove, and twist the tang anti-clockwise. This contracts the round part so it will slip in. When it is in all the way around, I keep twisting the tang anticlockwise until I've verified that it will rotate fairly easily, sliding in the groove. Just pushing the clip in doesn't seat it, but rotating it that way does - plus you can feel it get much easier to rotate, once it is properly seated.
I haven't seen your piston rings, and they are not original Honda so they may follow a different design. If the second ring is not tapered, it will not serve much of a purpose. However I agree that there is a convention that if a ring is marked, it will be on the upper side.
