@Jesse, yes it is always better to max passive/buff skills than attack skills. Except for poison mist, which should be maxed first unless RED skills are that different. My third job regret was not maxing poison mist sooner. If you already have a 4th job f/p mage, don’t bother with attack skills.
As for the ele staffs, at 195 you will get a mist eruption cooldown cutter. At freaking 195 :( (this is sad news for me, since my f/p is only 183). So, from 195+ probably the ele 6 is better, but I’m not going to regret having an ele 5 personally. Either are probably equivalently good until 195.