ok, so just for my own clarification and future reference (at least), here are my findings using chunky particles with inherit values turned on/off
The following are with render type normal, using chunky particles, and spawntype normal (0):
inherit (all) off: chunk faces north, stays where originally spawned
inherit_local on: chunk stays attached to object which spawned it, but only inherits relative xyz position, no rotation, which means it still faces north.
just inherit on: same as inherit_local
inheritvel on: chunk inherits initial velocity, which is 0 most times the engine starts allowing player interaction, so as with all inherit options turned off, chunk faces north and stays where it was originally spawned. Occasionally the particle is thrown at high velocity in the direction the spawn point is facing.
inherit_part on: same as inherit_local
inherit + inherit_local: part inherits local position, and rotates around the spawn point at a radius equal to the distance you are from the spawn position. While the spawn node moves in the z-axis, the particle also rotates around the original spawn position on the z axis. At no point does the facing of the particle change from north. If you walk forward, the distance the particle moves from the spawn point is forward, in whatever direction it is moving. If you walk backward (using backstep animation), the value is negative, so you can force the particle to return to the spawn point, with some error. Lets call this odd behavior 1.
inherit + inheritvel: same as inherit_local
inherit + inherit_part: same or similar to odd behavior 1
local + vel: same as inherit_local
local + part: part inherits the local position of the spawn point, and again gains no rotational values. However, as you walk, it gains a XY position bonus based on the distance from the original spawn point. If you walk in a positive direction, it goes forward faster. If you walk in a negative direction, it moves backward. Unlike the other odd behavior, this behavior is not dependent upon the facing of your character. Even after a lengthy battle, you can return to your spawn point and the particle will meet you there, without positional or rotational error. This could potentially be used as a very strange compass. Lets call this odd behavior 2.
vel + part: same as inherit_local
inherit + local + vel: may be exactly the same as odd behavior 1, but I can't tell if it is acting the same. When I back up, the part seems to stay in place, but as soon as I stop backing up, it sinks into the ground.
local + vel + part: seems to be the same as odd behavior 2.
Now I will go test some other render types.