Area of Effect abilities and targets

So I m having an issue in my Real time battles first person rpg, I have some AOE abilities that work fine when I have a target selected (it affects other enemies around the selected target as well), but if my main target is a bit away and I try to damage one of the non selected targets, I cast the ability and it works fine, but no damage to the non selected enemy, tried some of the raycast settings in the ability with no luck (I think i tried all the combinations).

Here is my target settings of the ability:

https://postimg.org/image/sxjrwynuz/

And the shortcut settings:

https://postimg.org/image/a6humstaj/

my goal is to be able to damage with these AOE abilities the surrounding enemies even if the are not my selected targets.

Also, I would like to ask if it's possible to automatically get the target that is nearest to the center of the screen as the main target? like TERA for example, which is auto-target as well as fps style of combat, which is what I m trying to achieve, so the nearest to my crosshair gets the target marker and becomes the main target.