You did it correctly, but if those skills are not in the game's Skillset called Character_Creation, the game will be upset and might give you 1 or 2 (if you don't edit your starting spells) but definitely not all 3.
To get that to work correctly, it is my understanding you'll have to copy over the (in stats) Character_Creation Skillset to your mod, by doing so you will overwrite it however and I'm not sure if an overwrite will make all other skills unavailable unless you copy each of them as well, and then add whatever additional skills you desire.
The alternative is creating a script that adds the abilities, and that is well beyond my capabilities as I'm no scripting beast. (-x
