Ahh, admittedly that description was written a little hastily - To answer your questions:
- The blue swirly icon is a fairly abstract "skill" action. These actions often have particularly special effects, such as copying skills, stealing dice, cleansing debuffs etc.
- The yellow arrow die is a "revive" skill that only appears on fainted characters. By swapping this die to another unit, after every other unit has acted that unit will revive a downed character.
- The set of icons beneath the unit's health bar indicates that unit's current debuffs and buffs.
Thank you for the feedback!