Help rotel pops when turning on and off

No its not bad to turn up an amp, and leave it on all the time because you can............it wont hurt anything, it will sound its best when warm and ready and uses very little power when idle. Many leave Solid State amps and gear on at all times, tubes are different because they will die faster when always left on but I even leave my tube pre amp on at all times, I just replace when needed as my tubes are too expensive.

I'm just guessing but when you turn your Sony receiver on you probably have to wait a few seconds for it to actually produce sound and also before it produces sound you will hear a soft click. That click is the protection circuit ensuring the power supply is stable before providing current to the speakers. Not all amps have this. Your Rotel doesn't have it.
My Portal Panache would thump when turned on and it would also keep producing sound for 5-10 seconds after it was powered down if the cdp was still playing. This is caused by the power supply capacitors keeping the amp operating while they discharge. As I said before it's not harmful but it can be annoying.
As for leaving the amp on, it's your electric bill.

Don't know about your Rotel model but if it has a speaker on/off switch make sure it's off before turning your amp on or off. If it doesn't you can plug a dummy load into the headphone jack which might mute the circuit. Good luck.

I have an old Sansui receiver that does the same thing. I put a larger wattage resistor across the "B" speaker leads, then before I turned it off, I just switched to the "B" speakers. When I power it up, it's on the "B" speakers, the load is absorbed by the resistors, then I switch to the "A" speakers, where my speakers are hooked up. Never a pop!

Is it critical to provide the amp a load on speaker b, or can I just switch it to b no worries?