You most likely have some kind of automatic timer set on the television. You need to change the settings of the timer.
Some ways to reduce how much energy is wasted would include, shutting off any lights that are not being used. Set thermostat to 78 and leave it. Turn the TV off and go for a walk.
When it is first turned on from being off for awhile.
You don't save money when TV/Laptop, PC is on Standby both when it is turned on or Standby you save no Electricity.
shutting off the valve
If you leave lights on when you are not using them and leave the TV on when you are not watching it, you are using too much electricity. You can actually cut your electric use and bill by shutting off lights when you are not using them, turning off appliances, including computers.
If I understand the question correctly, I'm assuming that you've watched the TV for awhile before you turn it off and you hear pops and cracks for awhile afterwards. If that's the case, then yes, it is normal. It's the plastic parts popping and cracking as they cool. Remember the basics? Heating causes things to expand and cooling causes them to contract. Hence, pops and cracks as the parts cool at different rates due th the densities of the different types of plastics used in the manufacturing of your set.
Where is the best place to park your ATV after shutting off the engine
Re-launch the Pandora app and press the stop button.
Check the sleep timer and or is the set getting too hot? I have mounted a small 6 inch fan (from Walmart) behind the tv so the air is blowing into the lower vent holes to move the hot air created by the set up and out.
Turning it off
turning the computer off
It's turning off