From his posts gums is addressing two very different things in my opinion. One is the use of automatics including autothrust and the other is basic airmanship.
Using automatics has improved safety considerably, however as we now see for a couple years, despite a record breaking low accident count, is the fact that pilots still need to be pilots and need basic airmanship. That said automatic flight systems are tools. Nothing more, nothing less. A professional pilot needs to know his automatics inside out as well as he needs to be able to fly manually if the need arises and of course has the ability to monitor what the aircraft and its system are doing. The latter one is actually the hardest task and human beings are not very good at monitoring,
Autothrust is very good at what it does, and over the long and incredibly boring hours of commercial flight, it is much better than any human being could ever be. However as any system it has its limitations, design criteria which it follows and different modes that work according to what state of flight they were designed to be used in. Using Level Change, or Flight Level Change, for a visual approach seems to be a rather odd use of autothrust mode in my opinion, certainly no mode i would ever use in the tiny boeing, however as i'm not rated on the huge twin i can't possibly comment if it is a normal use of AT mode there. In my outfit we would usually fly a visual in manual flight with the AT in arm (which provides low speed protection) and knowing that we have to set thrust manually.