I've recently committed to playing in a Pathfinder game, and I've become somewhat intrigued with the idea of playing a rogue/sorcerer multi-class character. I'm concerned, though, that as the game progresses I won't be able to keep up with my straightclassed party members in terms of damage output and survivability, essentially becoming a novelty character with a few parlor tricks and no real staying power ("pick this lock and then stay out of the way until we need you to cast detect magic on the loot").
That got me thinking: is there an effective way to identify class combinations which seem appealing up front, but which will fall behind as the characters level up (without actually taking the character through its paces in a game)?
I'm making a couple of assumptions here (NB, I'm limiting the scope of the question to core classes): first, that there are class combinations that DON'T scale well together into the mid- to late-game (if every class combination is equally (in)viable, this question is moot).
Second, that the definition of "working well together" precludes the necessity of min-maxing and shoehorning a multi-classed character into one specific playstyle ("this build works great as long as you only use sneak attacks"), though some combination will of course suit a style of play particularly well (you probably won't play a wizard/rogue if you're looking to be on the front lines and soak up punishment, for instance, but you might try cleric/fighter).
And finally, that a multi-classing character will limit the number of classes taken to two. It seems that multi-classed characters who take more than one additional class start to suffer from lack of focus.