Hybrid usually isn't particularly worthwhile for Warlock if you want Warlock as your main component due to all of its class features. Hybrid talent will only get you one back, and Warlocks tend to suffer when they don't have all their features working in tandem with each other. If you really want a ranged blaster that can do other things, then maybe you could combine Warlock with another Charisma or Constitution based class, but you'd probably be better off using Sorcerer to hybrid with.
Warlocks would be better off multiclassing by way of feat, but there are already so many good feats to take. For a Star Pact warlock, Improved Fate of the void is pretty great (especially if you can curse a bunch of enemies and manage to drop them all together, like if the sorcerer manages to blast them all with an area spell). Ulban's flare will boost your pact at-will quite well. Sacrifice to Caiphon is dawned amazing as it let's you regain your encounter powers if you miss all targets, which is great even if you take a little but of damage for it. Finally, Implement expertise is useful to prevent missing in the first place. With scaling defenses, each +1 to hit really can make a difference.
As a Star Pact Warlock, you'll want to decide whether you want to focus on Con as your main stat or Charisma. Don't make the mistake of pumping both at the expense of Intelligence. WotC went back and errata a bunch of star pact powers to allow them to use either of the two stats, so you really can choose. Charisma could be nice for skills, while Con will make you a lot more durable which can be great for a striker. Genasi makes a good Con-lock race from an optimization standpoint with +2 Con and Int and plenty of nifty options, while Half elf will add some versatility. It's just not as ideal stat wise unless you really want to generalize rather than specialize. If you'd rather go for Charisma, Tieflings have some amazing support and are pretty cool overall. El Adrian are also nice with a bonus class skill and some good feat support, plus an encounter teleport power. Gnomes are pretty much the same, stat wise, though the imagery of a small gnome staring up at the stars and waiting for them to stare back is pretty amusing.
