My answer is to reduce the burst range and the damage of burst spells.
For spells that render monsters and characters helpless, I removed the burst ability and gave the targets many chances to save versus helpless. Here are some sample powers. If these target-helpless powers are still too powerful for at-will we could always make the helpless effect last only one round. For example, a charmed character attacks his or her own party for 1 round and then the charm is broken.
Light Up
evocation/class lvl 1/You outline one foe in an aura of light even if invisible. The foe takes a Stealth -10 penalty./int vs int/reroll to maintain/As a free action, you create an adjustable radius of light for the party.
Fire Ball
evocation/class lvl 1/ranged 20/int vs dex/You shoot a fire ball doing int mod+1d6 fire damage+ongoing 3 damage./target's con vs your int ends/2 targets at 5th, 3 targets 10th lvl
Burning Hand
evocation/class lvl 2/at-will/int vs ac/You strike with your fire aura staff, dagger or wand doing 1[w]+int mod+1d6 fire damage+ongoing 3 damage./target's con vs your int ends
Explosive Rune
evocation/class lvl 3/ranged 20 burst 1/int vs dex/You send a steel ball with a fire rune scroll on it that explodes and does int mod+2 fire damage+ongoing 3 damage./target's con vs your int ends
Combust Foe
evocation/class lvl 4/ranged 20/int vs int/You cause 1 foe int mod+1d6 fire damage+ongoing 3 damage./target's con vs your int ends
Turn Alignment
enchantment/class lvl 1/encounter x1/ranged line of sight burst 2/cha vs wis/You cause foes of opposing alignments to have the frightened condition and try to get out of your line of sight.
Little Dance
enchantment/class lvl 2/ranged line of sight/cha vs wis/You force your enemy to laugh and or dance wasting their next turn.
Cause Sleep
enchantment/class lvl 3/ranged line of sight/cha vs wis/The sleeping foe wakes and ends the effect from an ally's standard action slap or 1 enemy's automatic hit and damage.
Hold Foe
enchantment/class lvl 4/ranged line of sight/cha vs wis/You bind your enemy who can not move and takes an automatic hit and normal damage. The enemy can roll a wis save versus your cha after being hit.
Command Foe
enchantment/class lvl 5/ranged line of sight/cha vs wis/You force 1 foe to approach you, or drop everything, or grovel on the ground before you./The foe rolls wis vs DC10+your cha mod at the beginning of its turn to try to break the control.
Charm Foe
enchantment/class lvl 6/ranged line of sight/cha vs wis/You force 1 foe to obey any command including attacking the self or an ally./The foe rolls wis vs DC10+your cha mod after attacking each time to try to break the charm. The victim also rolls wis vs your cha at the beginning of its turn.
For spells that render monsters and characters helpless, I removed the burst ability and gave the targets many chances to save versus helpless. Here are some sample powers. If these target-helpless powers are still too powerful for at-will we could always make the helpless effect last only one round. For example, a charmed character attacks his or her own party for 1 round and then the charm is broken.
Light Up
evocation/class lvl 1/You outline one foe in an aura of light even if invisible. The foe takes a Stealth -10 penalty./int vs int/reroll to maintain/As a free action, you create an adjustable radius of light for the party.
Fire Ball
evocation/class lvl 1/ranged 20/int vs dex/You shoot a fire ball doing int mod+1d6 fire damage+ongoing 3 damage./target's con vs your int ends/2 targets at 5th, 3 targets 10th lvl
Burning Hand
evocation/class lvl 2/at-will/int vs ac/You strike with your fire aura staff, dagger or wand doing 1[w]+int mod+1d6 fire damage+ongoing 3 damage./target's con vs your int ends
Explosive Rune
evocation/class lvl 3/ranged 20 burst 1/int vs dex/You send a steel ball with a fire rune scroll on it that explodes and does int mod+2 fire damage+ongoing 3 damage./target's con vs your int ends
Combust Foe
evocation/class lvl 4/ranged 20/int vs int/You cause 1 foe int mod+1d6 fire damage+ongoing 3 damage./target's con vs your int ends
Turn Alignment
enchantment/class lvl 1/encounter x1/ranged line of sight burst 2/cha vs wis/You cause foes of opposing alignments to have the frightened condition and try to get out of your line of sight.
Little Dance
enchantment/class lvl 2/ranged line of sight/cha vs wis/You force your enemy to laugh and or dance wasting their next turn.
Cause Sleep
enchantment/class lvl 3/ranged line of sight/cha vs wis/The sleeping foe wakes and ends the effect from an ally's standard action slap or 1 enemy's automatic hit and damage.
Hold Foe
enchantment/class lvl 4/ranged line of sight/cha vs wis/You bind your enemy who can not move and takes an automatic hit and normal damage. The enemy can roll a wis save versus your cha after being hit.
Command Foe
enchantment/class lvl 5/ranged line of sight/cha vs wis/You force 1 foe to approach you, or drop everything, or grovel on the ground before you./The foe rolls wis vs DC10+your cha mod at the beginning of its turn to try to break the control.
Charm Foe
enchantment/class lvl 6/ranged line of sight/cha vs wis/You force 1 foe to obey any command including attacking the self or an ally./The foe rolls wis vs DC10+your cha mod after attacking each time to try to break the charm. The victim also rolls wis vs your cha at the beginning of its turn.
