What I want to create is a Fighter/Rogue who can steal everything in plain sight and sneak around.
I am still thinking about my 2nd character, but I am leaning towards a mage, who might have some rogue-ish talents as well, but I am not sure yet?
Fighter/rogue doesn't synergize all that well if you're not planning to use daggers. You can do it, of course, but for combat purposes you'll probably find that having to dump points into Dex (which isn't as helpful for a non-dagger melee fighter as strength, speed, or perception, I don't think) makes you a little weak until you either get good items or level enough to cap STR anyway. Backstab damage is nice, but it doesn't compare or even hang out in the same neighborhood with a two-handed Flurry or Whirlwind.