Targeting is solely for user-input - it has nothing to do with output. Ask the question: what does the player have to do to cast this ability? Where does the cursor have to be?
Area of effect is a damage classification. Both "spelleffects" and "damagetype" are used for damage classification - and you've been adding spellaoe already. "spelleffects" is perhaps a poor choice of name for the parameter given it's used for non-spells, too, but "damagetype" is already taken.
"Area of effect" and "spellaoe" can be used interchangeably. I intend to merge/delete the old damage type templates (e.g. area of effect and single target) with the new ones (e.g. area damage and spell damage) - I just created new ones to make transitioning easier. Those two examples are ultimately the same thing - you'll notice the information is the same.
Regarding Brand's innate - spelleffects and damagetype both accept "Special" which says "See notes", and you should describe the multiple classifications in the ability details. The input is passive - the ability triggers itself. The damage over time is Persistent damage and explosion is Area damage.