CPSCRenderSprite
Unknown6 0x00 may be a boolean. Unknown6 0x00 looks to deal with how the effect determines alpha. 00 = black is alpha; 01 = black is black. But using other values makes it appear as normal. The following 3 bytes appear to have no effect on this either way.
Unknown8 determines distance from the spline where the effect will revolve around the spline based on the camera angle. Think of a barber pole, value determines radius of the red stripes.
Unknown9 affects strength of the sprite. Higher values = smaller sprite. Alpha intensity? Attenuation?
Unknown10 appears to be the opposite of Unknown9. Higher values = more opaque sprite.
Unknown15 affects size. I recommend values under 1000.
Unknown17 also affects size, but differently. Will have to investigate unknowns 14-18 to find exact relations between the values.

Unknowns 5, 7, 11, 12, 13, 14, 16, 18, 19, 20, 21 and 22 produced no noticeable effect at first glance.

Using the posted structs.

Entry
Boolean01: 00 = Normal; 01 = kills effect.
Boolean02: 00 = Normal; 01 = Only appears in background, pic.
Boolean03: ?
Boolean04: 00 = Black is alpha; 01 = Black is black.
Boolean05: ?
Boolean06: 00 = Normal; 01 = kills effect.
Boolean07: 00 = Always appears in foreground; 01 = normal, pic.
Boolean08: ?
Boolean09: ?
Boolean10: ?
Boolean11: ?
Boolean12: ?

Effect
Boolean13: 00 = Kills effect; 01 = normal.
Boolean14: ?

CPSCRenderSprite
Boolean15: ?
Boolean16: ?
Boolean17: ?
Boolean18: ?
Boolean19: ?
Boolean20: 00 = Normal; 01 = kills glow around sprites.
Boolean21: 00 = Normal; 01 = randomly twinkles/sparkles, pic.
Boolean22: ?

CPSCSpline
Boolean23: ?
Boolean24: 00 = Normal; 01 = kills refresh, pics: start, mid, end.
Boolean25: ?
Boolean26: 00 = Normal; 01 = Crash.
Boolean27: 00 = Crash; 01 = Normal.
Boolean28: ?

CPSCEmitterGeneric
Boolean29: ?
Boolean30: ?
Boolean31: 00 = Normal; 01 = Kills sprite refresh, pic, then fades away.
Boolean32: ?
Boolean33: ?
Boolean34: ?
Boolean35: ?
Boolean36: ?
Boolean37: ?
Boolean38: ?
Boolean39: ?
Boolean40: ?
Boolean41: ?
Boolean42: ?
Boolean43: 00 = Crash; 01 = Normal.

CPSCUpdateNormal
Boolean44: ?
Boolean45: ?
Boolean46: ?
Boolean47: 00 = Normal; 01 = Smooths/rounds the sprite.
Boolean48: ?
Boolean49: 00 = Sprites stay where they are generated, pic; 01 = Sprites stay where they are generated relative to the effect origin (normal).
Boolean50: 00 = Normal; 01 = kills effect.
Boolean51: ?
Boolean52: ?
Boolean53: ?
Boolean54: ?
Boolean55: ?
Boolean56: ?
Boolean57: ?
Boolean58: ?
Boolean59: ?
Boolean60: ?
Boolean61: ?
Boolean62: ?
Boolean63: 00 = Normal; 01 = Strobe/pulse flow, pic.

Because I suck at testing, I missed at least three things. Somewhere in bools 3, 5, 8-12, 14-19, 22-23, 25, 28-30, 32-42, 44-46, 48, and 51-62, something controls whether or not the effect eventually dies out, something acts similarly to bool 49 (maybe 48?), and something affects brightness/intensity. When all of these are 00, the changes are noticeable. When all of these are 01, everything appears as normal.

I've screwed with the effects before, so there are a few things I know can happen. My barebones effect won't do it, but there exists a way to make the effect interact with the landscape (elongated effect 158), so that it will not go through the ground. And augment effects twirl about in various directions, while my barebones effect only renders the sprite facing directly at the camera. Something makes that happen, just need to find out what.

I hate floats, so those go last.