I don't think Spirit makes sense. Might as well say Spirit can cause fire then. When they talk about energy manipulation there, they mean more like spatial distortions (that's why they say "bending energies around them" and don't say it is about manipulating energy directly). Spirit is already crazy-powerful compared to the other elements, so giving it more stuff doesn't seem like a good move. Pure Water is actually a very poor conductor of electricity. And overall lightning doesn't really fit its theme of liquids and entropy. Fire perhaps makes the the most sense of all, given its relationship to plasmas, but fire has quite a bit on its belt being able to do cold and flame already.
I mean, sure, you could justify lightning with anything. Heck, you could justify any element being able to make fire or cold. It would require somewhat extensive reasoning. However, at that point the elements stop being very unique and your choice of an element no longer matters.