Okay, this is super interesting, but also very OP. Darkvision, free Lucky feat, spells, skill prof, and other stuff depending on the subrace? Most races get like... One of that. Elves gain their weapon profs(Not even skill prof), lower darkvision, and high elves get spells, Eladrin get their teleport feature and darkvision, halflings get Lucky. I would recommend taking away the Lucky bit and skill prof, and just having the spells, darkvision, and subclass traits.
And speaking of the subclass traits, they need to be defined more- No saves for the Autumn's trait, for example, it just happens and people automatically think it's normal. Or the Winter, that needs to be much more defined- How long does it last for, does it need birds in the area, etc. Spring just needs to be nerfed, complete immunity to any damage three times per rest and auto resistance is crazy strong. Summer is fine.