i'll say the brake hose banjo bolt breaks easy if done up too tight.. .
if you are replacing the brake hoses, the nut on them can be a proper pain to undo, even with pipe spanners.. spray them with CRC or penetrene etc, wire brush the threads and find the best fitting spanner you can get your hands on for them.. (or get a professional to change them)
there is a locking compound on some of the caliper bolts also, i think the brake kit i bought had new bolts with locking compound on them already,
watch some youtube clips, there would be many videos on every aspect of what you are doing.. including how to set a torque wrench