You obviously can only have one keyboard layout at a time, which is what that language switch is for. But you can have multiple languages for autocorrection active at the same time, for example with Swiftkey. Which also works for the physical keyboard.
Typing on it needs some getting used to, just as flipping open the screen, and gets quicker fast (my hands are also rather small). With the device sitting on the desk and not picking it up, I can also open it with one hand, too, now, after having it in use for a week now.