The build seems to have Extend and Empower spell already.. The only metamagic spell that would increase output is Maximize spell. This build looks to focus on three schools, Transmutation, Abjuration, and Conjuration.(Relying on one school for damage..) That said, grabbing another school from the ground up or more metamagic might not help meet your expectations. In fact I think it would hurt more than help.
Either way, if you're unhappy with this build. You should be able to reincarnate. Unless you already reincarnated that individual toon. Reincarnation is per character slot, not per account.. You could reincarnate five characters in a day if you wanted.
From what I'm reading, it seems like undefind really would like more blasting power and isn't all that interested in support. A number of feats have been invested in support here, and trying to adjust the remaining feats to get more damage output might not really do the trick. Conjuration is included already and is a strong damage school. Maybe try switching around some of the spells to try and get a better damage selection.
A couple of possibilities:
1) Black Blade(9) and Greater Planar Binding(8) are both summon spells. You can only have one summon at a time, so you might drop one and take another damage spell. Meteor Swarm(9) would give you divine damage but without the feats your damage would be somewhat reduced. Or, at level 8, incendiary cloud would give you a cloud damage spell. Clouds are nice because they continue doing damage while you cast some more spells.
2) Flesh to Stone vs. Disintegrate. They're both nice, but have a lot of similarities. Both are kind of situational, both take one enemy out of the fight if it fails a save or else do nothing, they both rely on a fortitude save (although Flesh to Stone gets a +5 DC). You might replace one of them with another damage spell. Acid Fog or Isaac's Greater Missile storm are both possibilities. Acid Fog is a cloud (as described above), IGMS doesn't appear that useful in Hells' runs but seems to be very useful most other places and it has no save.
3) At level three you could switch out Displacement or Keen Edge and pick up Flame Arrow.
4) Break Enchantment is a kind of situational support spell. It might be switched for something (Freezing Fog).
I guess I'm suggesting a lot of clouds, but they are at least a nice way to enhance damage by letting you cast spells while they work.
Each character has a separate reincarnation timer. As long as you haven't reincarnated your sorcerer within the last 3 months you are free to reincarnate it (even if you've recently reincarnated a different character).
I'm sorry if the following comes off as too harsh to the builder, but it's unfortunate that this build was posted in the open subrace forum, because it's not effective in Legendary Level areas. The spell selection is very poor, Paragon Spell Penetration is delayed until level 75, Abjuration foci is a very bad choice for new players, and an entire lack of any Evocation, Illusion, or Necromancy foci is disappointing.
Basically, don't get down on this toon. Each toon has a separate reincarnation timer, otherwise everyone would have a different account per toon like I have for multi-boxing.
I personally think Evo and Necro are two of the most enjoyable classes in 0-60 play. Of course Illusion is very important if only for EV and survivability. If you haven't used a spell tome, then you can use one now for SF-ESF of another spell foci. But you should be able to right now anyways.