this depends on a lot of things, mostly, does your shot move?
generally the process involves creating a ‘clean plate’ – so make a clean frame without the fireman in it at all. just the building. put this layer under your original shot, then either paint the rope out using the clean plate as a source – or simply use a mask with feather to eliminate the rope, seeing through to your clean plate.
hmmm not sure i understand the problem, but are you viewing multiple views when your moving your camera? it’s the clearest means of understanding what the camera is doing. if the layers disappear altogether, my first thought is that you need to pull your camera further back, as you might have your camera position to see ‘beyond’ the layers. Regardless, checking out multiple views so you can see your camera in action, rather than just the results, is the key