You're right, helpless is too much, full-round action should be ok.
Feats: Weapon Finesse for one. Maybe Combat Reflexes as the second fighter bonus, or else Point Blank Shot. That leaves the 5 regular feats. Combat Casting, Spell Focus (evocation), Spell Focus (conjuration) perhaps. Could go for a skill booster, like Magical Aptitude. Not sure what else seems right for something that's kind of hybrid fighter/sorc. Improved Counterspell? Another melee feat?
Let's see, as it gets fighter bonus feats as if it were a 12th level fighter that is … seven fighter feats. That ought to be enough!
Hmm…
Fighter Feats: Combat Reflexes, Improved Initiative, Point Blank Shot, Rapid Shot, Weapon Focus (rattle), Weapon Specialization (rattle), Weapon Finesse
I fancied giving it Sidestep Charge or maybe Reckless Offense, but those turned out not to be Fighter Feats. Oh well.
For the regular we ought to focus on spellcasting. Let's see, for Spell Focus considerations we have:
Conjuration -
fog cloud,
stinking cloud
Evocation -
burning hands,
gust of wind,
fireball,
shout
Enchantment -
sleep,
hideous laughter
Illusion -
ventriloquism
Necromancy -
vampiric touch
Transmutation -
haste (harmless),
telekinesis (object)
Looks like your proposed Spell Foci of Evocation and Conjuration make sense, although I'm also tempted by Enchantment.
Shall we just give 'im all three? It's already got a respectable +2 DC to the "air" spells from Air Mastery of course, but in the grand tradition of 3E caster cheese we might as well munchkin-up a bit.
Wouldn't bother with Magical Aptitude since, like most skill feats, it's pretty useless. Combat Casting seems appropriate though. I'd suggest Eschew Materials for the last one, although we could assume the Screamer just has a spell component pouch like a regular caster if there's another feat you fancy.
Oh, and we might as well toss in the standard wizard's Scribe Scroll bonus feat in their for flavour.
That makes:
Feats: Combat Casting, Combat Reflexesᴮ
, Eschew Materials, Improved Initiativeᴮ, Point Blank Shotᴮ
, Rapid Shotᴮ, Scribe Scrollᴮ, Spell Focus (Conjuration, Evocation, Enchantment), Weapon Focus (rattle)ᴮ
, Weapon Specialization (rattle)ᴮ, Weapon Finesseᴮ*
*fighter bonus feat
Incidentally, I was seriously tempted by Energy Substitution [sonic] so it could "scream" a
fireball or
burning hands since it seemed so appropriate but I didn't fancy the extra Metamagic feat we'd need to waste as a prerequisite since it'd never get used.
That said, we could add it as a Special Ability…
Sonic Substitution (Sp): When the Screaming Child casts a spell with the acid, cold, electricity, or fire, it can modify the spell to use the sonic type of energy instead. The altered spell uses a spell slot of the spell’s normal level and works normally in all respects except the type of damage dealt.
Hmm… I like that. It does help explain the fellow's "Screaming" moniker.