Wow, it's hard to read your stuff.
Basically, though, what you're saying is that Line of Sight ... is the line that goes between an observer and an object of observation. Whether that's eye and item, transmitter and receiver (which, technically, would be line of transmission, but let's get past that), pointer and target, or mage and the soon-to-be-deceased, it remains the same.
Your initial post appeared to indicate that line of sight was defined by what was blocking it, as compared to whether or not it was clear. (Line-of-sight is, by general definition, clear - though you can state that in the case of a mobile target or viewer, objects intermittently interposing themselves makes for a broken line-of-sight. Or, also, that if you can only see part of them, that it's not a clear line-of-sight, though it is still line-of-sight.)
Interesting point - a mage needs LOS on the individual's aura, not on the individual themselves. As auras extend somewhat from the body, if you're too close to the corner, a good mage can still nail your sorry ass with a powerbolt.