I need to move the camera constantly to keep my characters in the frame.
You've probably figured this out by now, but the Home key will recentre the camera on your lead character, as will double clicking their portrait. Switching leaders will recentre the camera, as well, either by left clicking a portrait or using the F1-F4 hotkeys.
If you move your character by holding down the left mouse button to direct them the camera will stay focused on the lead character. If the camera is locked onto the lead character and you move by left clicking where you want to go, the camera will move with the character. However, if you move the camera so it is no longer locked on the lead character (by bumping the edges of the screen with your mouse, WASD or arrow keys) and then move by left clicking somewhere, the camera will not automatically move.
In the Game options you can disable edge panning, and adjust the pan speed.
Hold down the middle mouse button and move the mouse to rotate the camera. The environments were designed to be seen from a certain angle, so by default the range of rotation is limited. 360° camera rotation - How to