I had trouble at first navigating using the mouse and keys, but after i figured out how to navigate with the keyboard only it was much easier. Try using the Arrow keys with the Ctrl, and Shift Keys. Arrow Keys alone move you around. With the Ctrl key + Arrow Keys you can go Higher and Lower (Elevation), and Rotate the Camera. With the Ctrl Key + Shift Key + Arrow Keys you can Tilt the camera Up/Down, or Roll/Bank the camera. Using this method you don't even need to use the mouse, and you can zoom around over the landscape very intuitively & quickly.
If Planetside did give us a configurable mouse/keyboard option in the future, I would love to see an Unreal Engine/Editor scheme as a preset.
In UE4 you navigate very easily with just a three button mouse (no modifier keys required). You can move in any direction in both move/walk mode, or a strafe/sidestep mode, plus rotate, tilt, and elevation change all with a three button mouse. It's a very simple scheme that relies on you holding down LMB, RMB, or LMB+RMB while moving the mouse around. It's very similar to how Terragen works with keyboard navigation but all on the mouse.