The Incapacitator focuses on incapacitating his enemies rather than killing them. To this end, he employs save or suck spells, charm spells, and annoying hinderances such as walls and pits. The Incapacitator's job is to make the DPR character's job easy - they should be able to waltz right in there and do their thing.
|5||Greater Spell Focus: Conjuration|
|11||Spell Focus: Enchantment|
|17||Greater Spell Focus: Enchantment|
|19||Preferred Spell: Your Favorite!|
Charisma > Constitution > Dexterity > Intelligence/Wisdom > Strength. As long as you buff up Charisma and keep constitution fine, you should be fine. Get intelligence high if you want skills, it's just a matter of preference.
I would suggest this with a 20 point buy, after Gnome racial modifiers.
It's relatively balanced, focusing on dexterity for ranged, AC and reflex, and constitution for HP and fort saves. You can, of course, get charisma all the way up to 20 instead, but just pump charisma every level and you should be fine.
Spellcraft, use Magic Device, and Fly are all must have. It's also worth pumping Intimidate, Bluff, and Diplomacy, given that your charisma modifier will do some of the work for you.
Color Spray Silent Image
Scorching Ray - Here is one blaster spell to use when the time is right. It's not your game, but it will prove useful sometimes.
Ray of Exhaustion
Haste - Because if you don't get it, your team will be pissed at you.
Wall of Stone or Force
Summon Monster VI
Flesh to Stone Forceful Hand
Waves of Exhaustion
Reverse Gravity Grasping Hand
Mass Charm Monster
Prediction of Failure
Irresistible Dance Clenched Fist
Time stop - Duh
Hang back and bother people. Drop pits, walls, charms. Make sure that you know what saves your opponents are weak to, as you will have plenty of choices for spells. Don't try to get greedy - you are a support character, but you can win the fight on your own.
Obviously, your DPR is lackluster. You will need to rely on your friends to kill enemies.
Being small means a slower move speed. It will be hard to get out of melee if you find yourself in it.