[12 piece bucket]

12 piece,
again these are hard questions but i think there is some ambiguity as to what the straight line effort is.there appear to be two straight lines.
the aiming point is on the delivery line. which is equivalent to the plane line.which is on the ground. as you note, this guides the right forearm,clubshaft,and clubhead. this is the in and out portion of the inclined plane. the aiming point is on this line behind, in front of or at the ball.
when homer says that, "the HANDS must ALWAYS take one of the delivery paths (10-23)but even with the circle path the thrust is still a straight line effort toward the aiming point. this is a straight line effort because it is on an inclined plane. but it is only the outward portion of the inclined plane."there is also a strongly downward element of the three dimensional impact."(6-e-2-1)
now we have the straight line effort, not only OUT, but also DOWN. so we have a straight line delivery line or its equivalent and a straight line delivery path.
in the second edition homer defines 10-23-A,straight line as; "this pattern holds the hands on a delivery path that is a straight leading from the top-of-the-line hand position directly at the AIMING POINT. and 10-23-c top-arc-and straight line as; this pattern takes the hands beyond the top-of-the-line point, up and back along an arc that is retraced when the hands return to the top of the line point.they are then directed toward the BALL on the samepath as "A" above(straight line).
in subsequent editions he does not refer to the ball but only the aiming point.but he always references 2-j-3 when he refers to the aining point, which is again the delivery line.it appears homer was saying that both of these straight lines need to be coordinated(with the on plane right forearm?).
since every picture of a straight line delivery path in the book( ALL EDITIONS AS FAR AS I CAN SEE)regardless of lag loading,trigger type,assembly point,loading action,DELIVERY PATH, and release all go to the ball, i have to assume that this is still the case, regardless of the aiming point being in front of the ball.endless belt( straight line portion) to the ball then the the pulley encounter before or in front of or at the ball, then to the impact hand location.

denny pointed out to me (i am denny's co-worker) that when you go straight line to a point in front of the ball with #3pp or hands the right forearm is not on plane,it points beyond the delivery line.
in the 5th edition mr. kelley states in 7-3, "therefore,having all these precision relationships, a properly postioned right forearm at impact fix, presents the precise plane angle and the precise angle of attack and the precise angle of the delivery path per 2-j-3 and 7-23 for any elbow position.THEN THE DELIVERY PATH WILL ALWAYS INETRSECT THE ANGLE OF APPROACH AT THE IMPACT POINT(PER 1-L-5 THROUGH -15)WITHOUT DISTURBING THE CLUBHAED ORBIT."
hope this makes everyting clear. ha!ha!

You make some good points . . . My contention would be that AMBIGUOUS . . . could be? . . . I would submit that there are OPTIONS rather than AMBIGUITY. I would sum it up like this. There is Geometry and then there is Physics . . . and then there is Motion . . . and then there is ACTION . . .AND THEN there are ILLUSIONS:

The Geometry of Golf has two aspects – the facts and the illusions, visual and sensory. When facts are understood, the illusions not only cease to mislead but can be utilized.

There is the Geometry of the Delivery Paths (and Lines) which your quote from the 5th does a superb job of describing. So this quote we would assume to be a statement of FACT. And if this is the case, then why have an Aiming Point at all? Why not just take the hands straight down the Straight Line Portion of the Delivery Path to the ball?

I would submit that the reason for Aiming Point is to utilize and employ what could be argued to be an ILLUSION to bring MORE PRECISION to the Snap Releases of different clubs lengths. Remember Mr. K said that the Aiming Point was basically SUBJECTIVE and could only be identified by EXPERIMENT. So this is a personal thing. So if the ball works then fine use it. But if it don't. Then adjust the Aiming Point to control the release (OR adjust the ball position and have ONE Aiming Point for the same release feel for different clubs).

And then there is the Physics associated with the same Delivery Paths and the Endless Belt. Per 3-F-7-E, The correct concept of an “On Plane” procedure is driving the Club – not “a little downward and a little outward” – but “Down Plane”. Down Plane to full extension. Per 7-23 with the Straight Line Delivery Path "The Player envisions - is consciously aware of - a straight line wheel TRACK motion (rather than its rotation) toward and throught the ball or THROUGH THE AIMING POINT."

So we must remember that the Aiming Point Concept is primarily used to control the Snap Releases which per 10-24-E 10-24-E AUTOMATIC SNAP RELEASE This procedure drives the Lag Pressure Point through a Snap Release (6-N-0) as if there were to be no Release at all. . . .This action is possible only through use of the Aiming Point Concept (6-E-2). So is precision Impact control.

And then there is MOTION and ACTION. Earlier we were discussing Impact Hand Location. To me that is MOTION. All procedures produce some Impact Hand Location and that would be MOTION. Thrust on the other hand is ACTION and all Strokes have Thrust regardless of the method selected to accelerate the club. Per 7-23:

Normally, Delivery ACTION (Thrust) is "Cross-Line" - Delivery Motion is "On Line", even at Low Point, because the Delivery Path Angle (direction) is ALWAYS the Right Forearm Angle of Approach (7-3) even with the Circle Delivery Path.

This to me means ACTION (Thrust - Physics) is ALWAYS as above ALWAYS not just a little down and out but ALL THE WAY DOWN AND ALL THE WAY OUT . . . and if that is the Ball cool . . . but if that don't work then you have the Aiming Point . . . or if you don't like that then you have the Impact Fix Hand Location Procedure.