Thanks for all your advice... Here is the current build I am working with at the moment.
Str 12 +1
Dex 15 +2
Con 14 +2
Int 12 +1
Wis 10 +0
Cha 14 +2
Skills: Concentration 6 (4 Ranks, +2 Con), Knowledge (Arcana) +5 (4 Ranks, +1 Int),
Spell Craft +5 (4 Ranks, +1 Int), Use Magic Device +6 (4 Ranks, +2 Cha)
Feats
(Human) Point Blank Shot
(1) Precise Shot
(3) Sudden Still Spell
(6) Maximize Spell-like Ability (EB)
(9) Fly-by Attack
(12) Quicken Spell-like Ability (EB)
(15) Extra Invocation (Voracious Dispelling)
(18) Extra Invocation (Wall of Perilous Flame)
Invocations
(Warlock Level 1) Entropic Warding
(Warlock Level 2) Eldritch Spear
(Warlock Level 4) See the Unseen
(Warlock Level 6) Flee the Scene
(Warlock Level 8) Fell Flight
(Warlock Level 10) Eldritch Chain
(Warlock Level 11) Repelling Blast
(Warlock Level 13) Vitrolic Blast
(Warlock Level 15) Devour Magic
(Extra Invocation Level 15) Voracious Dispelling
(Warlock Level 16) Retributive Invisibility
(Warlock Level 18) Dark Discorporation
(Extra Invocation Level 18) Wall of Perilous Flame
(Warlock Level 20) Utterdark Blast
My primary use for this build is one for crowd control. He can use Eldritch Chain and Repelling Blast to knock 1 - 4 enemies back. Wall of Perilous Flame (which I won't get until much later in levels) will help break up enemies. The only invocation I have which relies on a saving throw (thus relies on a decent Charisma) is Repelling Blast.
Sudden Still Spell I will use with Flee the Scene in the event I get grappled.
Vitrolic Blast I took to get through any spell resistance.
Later in levels, I may get rid of Entropic Warding and pick up Devil's Sight. I think Entropic Warding will be good at early levels to prevent ranged attacks. Once I get Retributive Invisibility, I won't have much need for it.
I want both Devour Magic, which can be used at range, as well as Voracious Dispelling which is a higher level dispel, but with a range of touch.
I plan on taking Fly-by Attack so I can fly out from cover, use an invocation or Eldritch blast, then fly back it cover. Fly-by Attack grants a Standard Action in between a Move action (for those that don't know).
My only concerns are the way my ability points are distributed, and any must have feats I may be missing.
Thoughts?