1. If penalty kubbs did not have to be placed one baton length from corner stakes, then there would be a situation where a player could place a penalty kubb centered on the sideline, with the corner stake touching the back of the kubb, keeping the kubb upright, even when hit. I think this may be the reasoning for keeping kubbs a little bit away from field marking pins.
2a. It is my understanding that if you are shooting to topple the king to win the game legally, and your baton hits a kubb on your side of the pitch, then the kubb hits the king through the course of the motion, you would be declared the winner.
I agree with you from the perspective that this isn't well defined in rules. I am familiar with the US National Ruleset..here is an excerpt from the rulebook:
"The game is won by the team who topples all the kubbs in the upfield and on the baseline then topples the king."
"Topple" is defined in the glossary as:
A piece that has been struck by another piece as the result of a throw and becomes parallel to the ground. Pieces that fall over due to wind, uneven ground, or being jostled by a player are NOT considered toppled and should be placed back in their original position prior to the throw.
Therefore, in the scenario where a player throws a legal king shot, and the baton hits a kubb into a king and topples the king, then the king would be considered "toppled" by a "game piece" and the game won by the throwing team.
Now, let's say that you go for a king shot, hit a kubb on your side of the pitch, and miss the king. What then? The rules do not cover (as well) what to do if you hit your own kubb. I believe the spirit of the game (and looking at some other rules in Sec.II.B.) I would say to place the kubb back to its original position, and you do not get a re-throw. Not stated specifically in the US National Rules, however. This is how I would judge this situation anyway.
2b. I think that there are many situations that demand various placements for penalty kubbs. If you are playing a very good team, a kubb a meter behind the king is an easy shot for them. Sometimes you are just looking to soak 2 batons on a kubb to simply stay alive in a game. In this situation, I would not place the kubb behind the king. I think you see specific placement to the right because that is where no kubbs reside on the baseline perhaps. I would look at the post Garrick linked to on the matter of placement. Good stuff.