The appropriateness of what you are doing depends on many factors, none of which have anything to do with the mechanical functioning of your handgun. Things such as: are there other people where you live; are they trained in the proper handling of the specific firearm; are there children present; are there visitors, and so many more. Additionally, just for the sake of clarification, are you unholstering when you go to sleep or as soon as you arrive at home?
Now to try to answer your specific questions. First, the less administrative handling of a firearm there is, the less chance of a discharge that was not purposefully planned and carried out. (That covers possible ADs as well as the more frequent NDs.) Second, just as magazine springs neither "take a set" nor "wear out" from having rounds compressing them (it's the compression/extension cycling that does them in) your other springs will not wear out by just sitting there.
Putting your handgun on the nightstand in Condition #-whatever (unloaded meaning no magazine inserted) means you will have to perform the loading and cocking actions under both stress and (probably) in the dark if you need it for self defense purposes. Fine motor skills are not done optimally in either state, and even less so when both situations are present.
I am not going to tell you how to handle your firearm - that's a decision every person must make for themself. But now you have some information that may help you reach your own decision.