a. From what I can discern via web (UNCLAS) sources, and my old memory,
the SA-11 (SA-N-7 which I was more familiar with is in the same family) warhead
is HE/Frag, and is capable of the "up to down" or "up and over" engagement geometry in the end game.
Granted, a non maneuvering heavy may not need to be so engaged, but I suspect it is an option.
b. This is handy if your target is a maneuvering jet (fighter, attack, etc)
that changes it's movement vector in three dimensions (including down) as part of evasive maneuvering.
c. Don't recall how susceptible it is to chaff ... I suspect it depends on the cut of the chaff.
d. Not sure if that is how it typically engages a target, but that might explain
what SAMPUBLIUS was referring to in terms of the damage pattern.
e. The above is subject to errors in both my memory and what is (in open sources) available.
f. Note: Whomever is posting pictures, please compress the files and repost them.
They are way too big and are expanding the window frame which makes viewing the web page difficult.