First off, let me just say Rangers are an awesome twink class. On day one of Green they are ... how to put this delicately ... probably not the most powerful option. But on Blue, with a Fungi, Woodsman staff, and a haste cloak (plus a bunch of 10-dose SoW potions, so that you can survive until 30 when you can cast it yourself) the class is a
ton of fun to play.
As for Ranger/Rogue, I've never tried it, but I think it would make an amazing combo for one simple reason. Once you get past the "my Fungi makes me a tank" phase as a Ranger (and get to Velious if you're on Green), your next step in soloing is to rely
heavily on a single level 22 spell:
Panic Animal.
As long as you stick to animals and snare everything, this spell lets you take virtually no damage, because you keep the mob running away the entire time you fight. And hey, wouldn't a class that does tons of extra damage backstabbing make an
excellent partner for a class that spends the whole fight with the mob's back turned?