Okay okay but I have to say I've only played 2 warlocks ever one was a warforged warlock...
Phyrexia or die...
So, that being said, here are a few suggestions (not all need to be used, necessarily):
Add Cha to EB damage. This is really only a low-level boost.
Excellent and needed
EB scales like a rogue's Sneak Attack (this really only adds 1d6 later)
Not really that big a deal really, so it where does it make a difference exactly? hmm... Okay.
Create an invocation (probably blast shape) that lets you do a full-attack with your EB for the round.
You'll still be behind Eldritch Chain in terms of number of targets, but each blast will deal full damage. Thats really interesting actually thats perfect. Its not even a big deal, they should be able to do this and then there's the eldritch glaive with this might help
Perhaps set the number of invocations known to the warlock's level. This adds a total of 8 invocations over 20 levels.
Hm...
Yes. Yes... this... works I mean it keeps them from being sooo limited in thier choices
Have the DR scale at the same rate as the Dread Necromancer (roughly double that of the CA warlock). It would start at DR 2/Cold Iron at 2nd level, and increase two points every four levels.
Thank you may I have another. All class ability related DR on spell casters should scale like that probbably
Possibly drop Fiendish Resilience. It seems weak to the point of being useful, and I'm not sure the flavor is all that good. If anything, it could be used to call on some temporary HP in advance.
Yeah... Make it a specific bonus invocation that you get at that level. Granting temporary hp.
Add in some new blast shape invocations to help out a bit. Perhaps a 20' sphere at some range (60 feet? Medium range?) would work nicely.
I"m not sure that the shapes really matter that much... maybe if we let it make a wall or something? It has potential...
If I don't respond to something its not because I disagree or don't like the idea... I just don't go running off at the mouth when I feel my knowledge base is incomplete on a topic, or its summed up pretty damn well already. This was a case of the latter.
I didn't have enough info to "rebalance" the warlock myself. I just knew the Binder was already tier 3 and basically balanced so why change what works.
I think that warlock design works.
But ... one thing that bones the warlock as I recall... the selection of invocations they get is sooo small.
The list would prolly need to grow but I suppose they have the essentials...