Felon-
1. He's paying for his race/weapon choice somewhere. I don't know what his ability scores look like, but he's basically two points behind in accuracy in comparison to an equivalent human or dragonborn using a heavy blade. I'd say that's behind enough to call his attack bonus poor. If you were using point buy he may have purchased himself an 18 starting stat, but if he did, he's just losing out elsewhere, because that cost him 17 out of his initial 22 ability score points. A comparable human would have paid for only a 16, then used his racial bonus to top it off, gaining a lot of points to spend elsewhere.
2. I do agree that there's a disparity between the availability of damage boosting feats for the various classes. It looks like they provided a sample, so to speak, of the total feats they intend you to be using in the heroic tier. For example, WOTC seems to intend the game to be played so that every major military weapon has a superior weapon counterpart- but they only put the bastard sword in the PHB. I suspect that we'll be seeing an awful lot of increase in the base power level once these sorts of feats become available for other classes and weapon options. I have mixed feelings on this decision.
That being said, I don't consider the damage boosting feats that presently exist for spellcasters to be weak, even if they do have ability score prereqs, and even if they do only apply to certain elements. That seems to be how spellcasters specialize- by picking chosen elemental damage types. I expect that we won't see feats that remove these prereqs or allow other damage boosts, we'll instead see feats that give other benefits to fire mages, ice mages, etc, and which expand upon the prereqs as a basis for a particular build.
That isn't really related to [W] though.
3. You've got some area of effect attacks built right into the warlock class, you know. Your level 3 infernal pact encounter power is an area of attack, as is, I believe, your level 5. Both do decent amounts of damage that can be augmented by smart play and intelligent use of your curse.