Neonchameleon
Legend
Going with sorceror basics, you have a static damage modifier of +13 (+4 from Dex, +4 from Cha, +4 from staff, and +1 from Siberys Shard). So every target you hit is an extra +13 damage + your damage roll (although we halve the additional target damage as focus fire is better than spread out damage).
Chaos Bolt targets an average of two targets and you don't need to worry about friendly fire (just earth it into walls or flagstones) so there's no real need for friendly fire avoidance.
As for high damage encounter powers, you seem to like being on the front lines - a dangerous game with such a squishy class. I'd go for some ranged Burst 1s. So possibly Blazing Starfall rather than Burning Spray once you have your Staff Expertise. 2 points less damage, but you can land it in much more dangerous spots without exposing yourself. And Radiant Damage generally rocks.
Encounter 1: You picked a one or two target power. Not bad but it requires risking yourself by being almost in melee range. So I'd go for Mists of Disarray - fling it past your front line people. And it has a decent potential to be able to rearrange the enemy so their archers and mages are in close combat with your defender.
Encounter 3: Forget what I just said about risking yourself. There's one extremely high damage power here. Flame Spiral. You don't seem to mind the front lines much, and it's three targets and friendly. But the really high damage element is the effect line - 1d6+9 damage without a to hit roll if any enemy is next to you (remember because it's a damage roll you get your dex and your implement although not your charisma). Hug your defender if you want this - or hide behind him if you don't (and remember you are very squishy). Your current encounter 3 isn't friendly and is effectively a burst 1 with a higher chance of missing.
Encounter 7: Spark Form works. Multitarget and can take you off the front line after causing sheer mayhem with your Flame Spiral. Leave yourself not engaged and then use your move action to hide behind things or run like buggery.
Daily 1: If you want single target damage, go for Grounding Rebuke - you don't normally use your immediate action, so it's essentially a free hit doing d10+13 damage and with a slide thrown in. Anti-solo work - solos hate being blinded so go Blinding Bolt. Anti-minion work Howling Tempest creates a nice movable zone to wipe them out.
Daily 5: Everywhere and Nowhere belongs to gnomes for solo-fighting. Or other people who go invisible a lot. It's a great power if you leverage it but I don't think you have. Single target damage: Two powers (Thunder Leap and Acidic Impantation can give you two damage rolls against your foe, but both can be very unfriendly. One power (Slaad's Gambit) is an interrupt (so effectively a free attack) and pulls you to safety, probably winning the survivability stakes. And there's Glacial Armour if you know you're likely to be hit.
