I like this idea of perks, as stated some do need work and im sure some good ideas will come. I do have one suggestion to come along with this update if possible.
I have always liked the style of the skill cape hood when worn, but when you look at the various "master skilled" npc's scattered over runescape (where you get the skill capes from when acheived) You will notice some of them are wearing the hood down and it just hangs over/on top of the cape. I love this and i think it would be a great addition to the skill capes update; to
give players the option to operate the hood in some way and choose between having the hood up or down
(This is purely cosmetic as the cape provides the bonuses).
Stay