1. spark, a card that does 3 damage once, and is only really useful for being immolated.
WRONG A Momentum/Unstoppable or other Hp-buffer can make it a sustained creature. Also, Fractalling it has had uses with Sky Blitz and Chimera for an OHK. More so, mutation fodder. The free cost of the card is what makes it a good card in so many other ways than just Immolation fodder. Also can be a "free" death trigger, only being that it takes up a card slot in you deck.
2. lightning, a decent direct damage spell that is outshined by fire lance and drain life
WRONG It has strength in that it doesn't require a quanta sink to deal what is significant damage. It outshines the other bolts in that its damage is more than the common HP of creatures, including several creatures from Gravity and Earth, while having only the quanta required to cast the spell. We don't need too many quanta sink cards, which Fractal (though more of a duo+ quanta sink card) already fills that spot in aether.
3. 2 immaterial creatures
Perfectly fine A big one and a small one.
4. 2 cards that make creatures immaterial
Not too much, not too little Alchemy and the alchemist (the Nymph).
5. 2 other cards that target creatures and give you a beneficial effect from them
Not a big issue I would honestly say that one is enough per element, given they can use opponent creatures.
6. 1 creature that can take advantage of either of the two above points
Agreed First it has 3, given you throw in an HP buff onto a Spark, and the Nymph. Second, I do agree that it's short on creatures that can be target, even in the general spectrum of all cards, since only one is self-sustainable otherwise and common.
7. mindgate, silence, and lobotomizer (no issues)
Nothing to say since there are no issues