I think you might want to leave out Ray of Light. It could be far too powerful with Hope since this breaks the "6 of" rule with next to no investment, especially relative to Fractal (I could be wrong though). I think a low cost would be okay, since the creatures it spawns are very weak and take up the limited creature slots (speaking of which, this could buff Flooding!). However, I think 0+0 is too low mainly because it would be too powerful with Immolation and in some Rainbows.
I agree on this point, but more so with Firefly due to the fact it's stronger than all the other quantum generating creatures and if you get it it comes for a lot cheaper than a normal firefly. I would leave the Firefly out instead, because Ray of Light didn't prove to be much of a problem as shown by Luminiferous Aether (http://elementscommunity.org/forum/index.php/topic,7231.0.html).
Taking Luminiferous Aether into consideration - it should probably cost something to play as well, like 3-5 
since this is also easy mutation fodder for Fallen Druid.
thats a neat card.
I really think this should be free, so it can produce quanta indirectly, as the only source. The one activation lets you run off mark, so it should be ok.
The firefly, especially the elite is kinda beefy. I dont know about putting on the card, but in code behind the scenes I see a weighted probability, towards smaller creatures/needed creatures. Im not sure though, it should be pretty random. I also considered taking some HP, like casting cost, to spawn the creature.
With All six in play, you should have and keep a full field of tiny quanta producing creatures. Looking over them, the only one that is really going to call for a raise in cost is the elite firefly. Everything else is free, or costs one quanta.
What if I removed Firefly? I think its too big of a nerf. It takes an option out of the unuppgraded, a 33% reduction in usefulness, and removes any sting from the card. In the upped version, I think it is the reason an activation cost is required at all.
I have considered the card in both rainbow, where its handy, but not really spectacular, and as a pure quanta source, which Ill extrapolate on below.
Using all upped cards
With Six of these in your deck as the only quanta source and zero cost card, you should get one or two in first draw.
you play one and end your turn.
you spawn a creature, maybe play another.
you are just now making quanta.
as a pure quanta source it is slow, but has potential.
cards you would run from this:
holy flash and buckler, blessing, maybe pegasus or angel, sanctuary
fog, storm, animate, shockwave, maybe wyrm n wings
antlion, armor, PA, quicksand, warden, maybe skin and golem
explosion, spectre, cremate, golem, maybe phoenix and buckler
the upped version has a pretty nice spread.
the standard card can only produce three creatures, dragonfly, gnome rider and firefly, giving only light, earth, and wind.
the cards open are different.
blessing, angel, sanctuary, reflect and solar, holy light, pegasus is a maybe
fog, flying weapon, shockwave and storm, maybe wyrm,
warden, antlion, PA, armor maybe skin,
you just cant take the bigger cards and you dont have two critters pumping fire.
In these scenarios, the firefly is like the biggest critter you got, except for costly wyrms and pagasi.
Not this thing screams pendulums, so there is some room for modification, and it supplies a healthy spread of accessory cards without needing quantum towers.
With Mitosis, Fractal and existing card spawners, the queen and pharoah, I think its ok at its cost.
Im interested in how other people would exploit it, I just think its too slow to be more expensive, maybe a 2|1 activation?
