The C4D rendering engine is slow. You are using adaptive resolution and that is what is causing the 1/4 resolution preview while you drag the camera tool. Precise camera movements are much easier to do if you enable multiple views and use the various composition panel views to move the camera into the proper position. For a lot of camera animation, a two-node camera is easier to manipulate than a one-node camera.
It just takes practice. I've been using After Effects since it was first invented and I never use the camera tools for anything more than a quick adjustment to get the camera close to where it needs to be. I almost always have the previews set to Final Quality and in the latest versions of AE I have Draft 3D turned on. If I am using the C4D rendering engine I almost always set up my camera moves and lights using the Classic 3D renderer because it is easier to use. When the camera and lights are properly setup and the blocking and timing has been worked out I will switch to the C4D rendering engine to extrude shape layers or text. I can only think of one comp that I have created for a client where I needed to bend a layer.
I always fine-tune camera movements using multiple views and the transform properties in the timeline. If you are still having problems, spend some time with the User Guide.