Plane Sailing
Astral Admin - Mwahahaha!
Oh, one other thing...
for some spells, I would allow a wizard to alter the type of damage a spell does when they first choose a power, that way if they want to theme their character around a certain type of energy, say lightning, they suddenly have spells to choose from.
So if a spell normally does fire or cold, they can choose instead for it to do lightning. Once they choose that, it stays that way, no switching back and forth, but it does give them a bit more choice.
I can see a couple of potential issues with that:
1. WotC have made more of an effort to give specific themes to energy effects now (e.g. fire and acid are likely to do ongoing damage, thunder might push people, cold might slow or immobilise them). Pulling an energy switcheroo would get in the way of that.
2. Wizards have quite a distinct balance of spells - lots of fire and cold, some lightning and force, only a couple of acid, necrotic, psychic and radiant for instance. If a wizard makes all his things psychic damage, or radiant damage, he'll be facing a lot less resistances and will be treading on the toes of other classes (warlock for psychic/necrotic, clerics/paladins for radiant).
These might not be an issue, but are worth considering.
Cheers