Guild Wars 2

Can someone explain what the regeneration and cleansing actually applies to?

I’m firing through a water field, granting regeneration, but it’s not actually being applied to myself unless I’m practically point blank.

Am I intended to ‘coat’ the projectile with water or light, and have it pass through an ALLY? This really isn’t very clear to me, and it doesn’t help that there really isn’t any proper way to AA on an ally unless they’re standing in between you and the enemy, or you aim from first person view which is sketchy at best..

It applies to allies that the projectile passes through, not yourself. Unless, like you said, you are so close to the enemy that it causes the projectile to register as hitting you too.

When your projectile hits an enemy it creates a small AoE which applies the effect. If you want the effect, hit enemies on melee range.