Simply stated, can MOPixels and MOSParticles be rotated around like MOSRotatings and AEmitters?
I want to attach a glow to a MOPixel and have it change the direction it faces towards the enemy via lua, but it doesn't seem to actually rotate the glow.

Also, the .ini coding allows glows to be attached directly AEmitters, but in-game they don't seem to actually glow.
Might just be me not noticing stuff though,.

Glows cannot be rotated.
It might be a technical thing (they're of different bitdepth than the rest of the game) or it simply wasn't implemented at the time.

Glows also fail to show up on anything but MOPixels/MOSprites.

Well that's kinda sad.
Sorry if this is a totally obvious question, but what exactly are MOSprites?

Mass Object Sprites, pixels with a sprite on them.

Actually that'd be Movable Object Sprites.

I thought those were called MOSParticles.

edit: unless MOSParticle is really the same thing except with a "particle" added to the end.

Yes MOSParticle is Movable Object Sprite Particle. It effectively has the same properties as an MOPixel, but is sprited instead of engine-coloured.

You could rotate the glow graphically in an image editor, and make multiple glows of one shape rotating, and use them as 'frames' for an 'animation' of 'rotating' your glow.

Remember that glows can't be more than one frame, so you do have to make a glow for each different rotation. Hence the 'inverted commas' in the post above.