Apricot's ability is once per battle, not once per turn, though it's still incredible. Dendrobium's double skill chances do apply for her double attack (other double attacks also benefit from the first-turn buffs of Cymbidium, Daisy, Anthurium etc. if they trigger on the first turn).

It's worth noting that Lycoris' blooming is so overwhelmingly powerful (who needs stats when you have the best offensive ability and second-best defensive ability in the game?) that she should be an instant pick for min-maxers, but her blooming is late enough that it won't be too relevant to Nutaku players. If you're in for the long haul, you'll also want to pick up a dodge rainbow (which Lycoris is) for the amazing synergy between dodging and the attachable taunt ability, which will make you all but immune to non-skill attacks.

But yeah, I agree that rainbows should always be chosen based on looks. There aren't many maps that require min-maxing, even on DMM, and these that do exist can mostly be cheesed with the right golds.