Shin Okada said:
Of course, if you are a high level character and have enough money to buy a lot of magic items, there are ways to soften the disadvantages that a small humanoid has. But that means you are investing your money (and/or your XP in case you make it by yourself) to items which usual medium-sized warlock doesn't need. It is called a disadvantage, doesn't it?
Easy travel is only 1500 gp. That makes +1 armor of easy travel 2660-2800 gp. I'd hardly consider that much money needing "high level" to aquire.
And, considering the weight of armor and normal 'adventuring' gear, even your Str 8 human is going to be dipping into medium load pretty darn quick. Again, they'll be needing to spend (or make) items to 'soften the disadvantages' of not being able to carry much.
So, again, no difference between small or medium humanoid on that front.
Shin Okada said:
If you are not maxing out Dex or at least put 6 ability points on Dex, then the halfling's advantage is +1 bonus and +1AC/Attack from small size. But, Warlock is indeed a multi-ability score-defendant class. And better to have high Con as it is only slightly tougher than sorcerers and wizards. And better to have high Int to max-out many skill though it has only 2+Int bonus skill points. Warlock is not just feats defendant class but also a skill defendant class.
Need high Dex & High CHA. Unless you are making a character with, say, 50 point-buy or something, putting extra 2-points on str for making a halfling warlock "workable" is painful.
A 16 dex in point buy is using 6 ability points. And, when your main weapon is, you know, a ranged touch attack, that +1 bonus to hit is like a built in Weapon Focus in a class that's feat dependant.
Everything you say about the other stats can go for *any* class, so, honestly, it's irrelevant. Every class can use more HP (even barbarians). Every class can use more skill points (even rogues).
With a 32 point buy, my halfling warlock started out with 8,16,14,14,14,14. I dont' think there's anything wrong with that. There's only a couple of skills I really care to max out (UMD and Concentration). I even took 5 ranks in a cross-class skill. When any class, not just warlock, wants to focus on *everything*, there's never enough skill points. So, honestly, it's better to focus on the essentials, and have the party pick up the slack.
The only point you do have is the charisma thing, and even *then*, it's entirely possible to take invocations that don't force saving throws, meaning the charisma is pointless except for UMD. Even then, at higher levels, it also becomes useless, because you can max out the skill to beyond needing to roll a die to use any item.