Slowing down the rotation is unnecessary. It's fine without the LMG. If you want to suggest something specifically for Equinox, the best route is to improve core mechanics by way of ...mechanics. (Things like making NG lasts longer.) The best changes are the ones that can improve a talent directly, but also improve other aspects slightly. Not fulfilling a niche, or becoming niche in an aspect, these are fine. But if it fills a niche role, it shouldn't be too strong in other aspects of gameplay, thus allowing the other talents to fill a niche.
There's no reason not to make Equinox an "all-around" talent. Min/Max with Equinox shouldn't be a thing (no niche role.) If Equinox is good for single-target, multi-dot, and AOE, then let Sunfall and IS be great in some aspects.
Game design isn't too hard. Settling on an idea is difficult. From the basics, we get the complexity. Since the basics of Balance druid are not changing (or very small changes), we need to suggest ideas which try their best to build off the basics.