Twitch is one of my favorites to play, but at the same time, I hate having one in the game. I think you'll understand after a few games.
Yes his range is short, but it's better than no range, and if you have a good stun in lane with you (Sion, Veigar are my faves) you will almost certainly get first blood. If your enemy gets wise to your stealth, I would defenitely recommend grabbing an orcale's early. This will allow you to kill pink wards, and force them to either hug the tower or get orcale's themselves. If they get one, you just call in the jungler and gank him. Also, I'm pretty sure orcale's has a much smaller detection radius that pinks, so you can still sneak around a little bit. Hope that helps!