You don't HAVE to mirco manage your pet much as a ARN, but once you get to SCH or SMN, micro managing them will make the difference between the standard cookie-cutter smn/sch to one that really shines. I micro everything about my SCH's Eos spells. I always keep her near the tank while keeping myself out of danger and making sure that mine and her heals aren't working against each other but assisting as much as possible.
EDIT: there are certain spells/commands you can do also at the same time assuming you do them in correct order. Example; i can have Eos use embrace on one targert and then i can instantly start casting Physic on another, but, i can not order her to case Embrace if i start casting Phsyic first. Granted, she will automatically start casting Embrace after a member's hp is so low, but some times, like fighting the dragon in longstop dungeon, that slight delay in her casting is a few seconds to long and someone doesn't survive.
Edited, Sep 6th 2013 12:07pm by RyanSquires