Be careful as you are conflating several different things.
1. Whether or not you see the Standby light, when the TV is off, is a configurable option in the menus. If you enable it, you'll always see the Standby light immediately with no delays every time you put the TV in standby. There's never any delay before seeing the light, doesn't matter if it's doing an auto-cycle or not.
2. If the panel is dark with all sources off, you should be seeing the "no signal" screen. Either you get the plain text version, or you get the version which uses the Gallery pictures, if you've set that option. This means that if you see a black screen, it's in stanbdy or you are feeding it a black screen.
It adds more information.
If you're not using a USB light, your only chance to know about it running is to (a) hear the lack of a quiet click when you turn the TV into standby, and (b) hear the quiet click a few minutes later to know it's finished. It's very easy to miss it.
But if you are using a USB light, you have a very nice clear way of knowing that it's running and when it has finished!
Yes, with the bolded words removed. See above