Hey brtizl, I haven’t used gideros enough (literally only have a few hours on it) but I’ll try to answer your questions the best I can.
First and forth most, here is the reference: http://docs.giderosmobile.com/reference/gideros/Particles#Particles
This is where I’m answering most of your questions from.
Are there any limitations to particles in Gideros?
I haven’t used them enough to know yet! I’ll ask the Gideros community and see what they say.
Can you attach things to them?
Quickly skimming over the reference, the only form of “attaching things” I seem to see is a tagging system, but it looks like it’s still in development:
Particles:setParticleTag ()
Sets the tag associated to the given particle
and
(string) = Particles:getParticleTag(i)
Returns the tag associated to the given particle
Can you change the looks of individual particles?
Some of these are still in development from what I see, but you can change the angle, color, decay, position, size, speed, ttl, and tag using the particle index number.
It doesn’t look like you can change the texture individually with the particle index number, Particles:setTexture(texture) sets texture to all particles.
Scale and rotation?
Yes. Particles:setParticleSize(i, size) and Particles:setParticleAngle(i, angle)
Change the “sprite”?
I’m not sure what you exactly mean by change the sprite, but the documentation says particles inherit from sprites, so I’m assuming you would use the sprite class to change the sprite for things you cant do with the particle class:
http://docs.giderosmobile.com/reference/gideros/Sprite#Sprite
There seem to be a lot more transformation options using the sprite class.