1. The green squares should animate together side by side. This applies
to the blue ones as well.
2. The time values indicate when the squares should reach the
corresponding reference square.
3. The total distance is 0+40+80+24.14=144.14
a. The "green animation" is 9 sec and linear so each interval
should get 3 sec.
b. The "blue animation" is 8 sec and paced so the intervals
should get 2.22, 4.44 and 1.34 sec each.

Here comes a more detailed description of the animation.
The left green square (LG) is animated by animating the points with
a value array, consisting of 4 lists of points. This is an animation
with calc-mode=linear so an equal amount of time should be spent on
all 4 intervals. The right green square (RG) is animated by a simple
linear motion followed by a scale to follow LG.
The last scale by 1.9428 correspond to a movement of the lover right
corner of the square by sqrt((30*0.9428)^2 + (30*0.9428)^2) which is
approximately 40 distance units. This is the same distance as the first
interval in the values array (and half the second interval).
The length (in terms of distance) is not really important for the
green squares but for the blue squares which are animated with
calc-mode=paced the length is used to calculate the time for each
interval.
Since the first and last interval are of the same length which
totals to the length of the middle interval, the interval should
be given time according to [27.75%(2.22sec);55.5%(4.44sec);16.75%(1.34sec)].
So the left blue square (LR) is animated just as the LG square but
with calc-mode=paced. The same applies to the right blue square (RR)
that has default calc-mode (paced for animateMotion) compablue to the
RG square that has calc-mode=linear.
The calc-mode for the scale of RR (and RG) is not important since
it's not a value list type of animation.