My worry would not so much be the amplifier as the power supply. Each year a considerable number of power supplies, often when in stand-by mode, have a sudden break-down and catch fire.
The problem with repeatedly disconnecting these SMPS bricks is the large current inrush that happens when you reconnect them. Those first few cycles of AC can carry quite a load of current and that will shorten the life of the power supply quite noticeably.
They are actually designed to be plugged in and powered on continuously.
In fact, powering them down and back up repeatedly could well be the cause of the catastrophic failures you mentioned.
This problem is further exacerbated by the bulk capacitors in the amplifier itself. Generally they are left charged all the time power is connected. Add this inrush of current to that of the brick itself and you have a power supply killer.
I ran into this first with PC power supplies... they are designed to be powered up all the time. A couple of my computer clients were turning them off, via the babysitter switch on the back, every time they shut down their computer. When they came to me their complaint was that power supplies were only lasting a few
months. So I replaced the supply and told them to stop turning off the back switch... Haven't hear from them since.
Plug it in, hook up the amp and power supply and leave it that way. Use the front panel switch on the amp to turn it on and off.