Hi there! I'm no expert when it comes to this strategic things but I do recommend switching places of your Sailor Sakura with your Main.. Sailor Sakura is meant for receiving damage as she is more tankier and she benefits from being attacked as she gets additional attack and heals herself.. And on the latter part of your post, if you're talking about the mood of your main character, it is much better if you make it +nin to max your healing capability.. :))

hmmm.. I do recommend placing your (-) mark with the Atk attribute as your main doesnt do any tai/nin attacks.. On the other hand, Life/Def/Res is also important to your main so the best viable option for me to place (-) mark is with Atk.. hahahaha, don't worry, in the long run, your dangos will stackup .. i have 400+ dangos right now, waiting to be eaten in my inventory xD