VFX questions

okay, so in my various wanderings through the world of VFXes, I've come up with a few questions...

SPLAT: what is it and has anyone successfully used it? I thought I knew what it was for but I can't get it to do anything at all... :s
EMISSION/ CHUNKY: whats this?
OTHER/ INHERITANCE: whats this?
OTHER/ COLLISION: where is the sprite center and is there any way to change it? for billboard-to-world-Z, the center seems to be way below where the actual particles are... i would like it to be in the center of the particle when aligned in this way.
OTHER/ POINT TO POINT: if one is using a placeable to travel from caster to target, then when is point to point ever needed? what has anyone used it for?

If anyone knows any of the answers to these, I'd be happy to update the VFX Wiki Page, but right now its a little sparse with regards the above...

Thanks in advance if anyone knows anything about any of the above. even a little extra info would really help!