I've gotten far with Life and Death both as secondary schools. I got the healing spells for Life and I like the attack/steal health with Death. But seeing as how some gaming features may change, you might stick strictly with Life.
My lvl 45 storm wizard also has life as it's secondary. I soloed most of the game. Not only was the ability to heal myself welcome, but I love using the life attack spells on storm monsters. I picked up some balance shields in Krok, but that is all I have needed from any of the other schools so far. I have five training points and no idea what to use them on. :?
For a Storm wizard I would choose either Life or Myth. Life for the healing cause sTorm is at a huge health disadvantage. Myth would be good cause storm enemies boost myth attacks. Also Myth has earthquake which is a good arena spell if you do try arena.
Also prisms are very good against same school foes and they will be used a lot. I used my prisms a ton throughout the game and they are super helpful no matter what world your in.
Life is a good choice for storm only because you need the ability to heal. I have a grandmaster storm, whose secondary school is myth and has some life spells. The earthquake really comes in handy as does the minotaur move to bust shields and take major damage with boosts. My wizard is in the top 100 in pvp, just in case you were wondering.