It's probably just a matter of taste... I use another view in radiant, in edit/preferences the 3rd from left, where u can see all three views, and the 3D-view as well.
Moving the camera by mouse is best imho, because it's faster than by keys.
Click the camera movement *) to mode 2 (eye-symbol with a 2) and
with mousepointer in the 3D-view

x-move and z-rotate the cam by moving the mouse with right mouse button pressed (rmb)

yz-move the cam by moving the mouse with Ctrl+rmb

yz-rotate the cam by moving the mouse with Ctrl+Shift+rmb
with mousepointer in a 2D-view

pan the view by moving the mouse with rmb

zoom the view by mousewheel
*) in case above doesn't work, you might accidentally have pressed the 'm' key which will change the cam movement to the next mode.