Wow, I find this thread extremely interesting. I did not realize there was so much ambiguity here, though I think it is simpler than people are making it. First, the rules in question are basically in regards to how does one target a wall. I think the first thing we need to do therefore is refresh ourselves on the rules for targeting. In order to target an object three things must be true:
1. You have LOS to the object.
2. The object is within range.
3. The object is a legal target for whatever effect you are using on it.
Now, the rules that have been discussed are simply clarifying how these targeting rules are applied with regards to walls. Since walls do not exist within a zone, the normal rules for determining 1 and 2 above can not be used. It doesn't make sense to draw a line to the center of the zone containing a wall, because walls are not within a zone. So, instead we have:
1. Instead of drawing a line to the center of the zone containing the target object, for a wall you draw a line to the center of the zone border containing the wall.
2. Instead of counting the number of zones up to the one containing the target object, you count the number of zones up to a zone adjacent to the target wall.
Now, the problem at hand seems to be the fact that there is no rule to determine which adjacent zone you must use when counting range. It would be much easier if they stated the nearest adjacent zone, which is how I have typically interpreted it. This interpretation would mean that any attack with a minimum range of 1 would be incapable of attacking a wall bordering it's zone. However, rules as written lacks this specification which grants the player the option of which zone they would like to use when counting range. Thus, strictly going by the rules as written, you get to choose whether the bordering wall is 0 zones away or 1 zone away whenever you target it.
This is not something I realized until now, and is an interesting spin on things. Up until now I've been considering walls a paradox, because measuring distance to them using the nearest adjacent zone would mean that the wall is closer to the attacker than the attacker is to the wall. Because, measuring distance to a bordering wall from an attacking creature (or conjuration) would result in 0 zones away (the nearest zone adjacent to the wall is the one your creature's in) while measuring from the same wall to the same creature would be 1 zone away (the zone adjacent to the wall).
Now, instead we have a paradox similar to Schrodinger's Cat, where the wall is both 0 and 1 zone away from you, and you don't know which until you decide to target it, lol.