Magic tricks must be casted and the manually click on the extra action slot or use a macro. If silence prevent of use Ferret Sickle/Flame Dance, it should prevent any single herald skill of be casted, and maybe warden pets skills as well.
And concerning to the LoS issue, well... there are too many skills, npc's and defensive buildings that hit through walls, and iirc the game admin said that as far as you don't abuse it to kill permanent buildings inside the castle it's not an exploit, and it has a cd of 12s and a low range so this leads me to the next question. What type of bug report is this? Somebody killed me with skill X, nerf them QQ!