How Secure is my iPhone/ provide automatic re-enable of a phone that has set do not disturb.

Question

There are many articles about how smart phones can be hacked to do things not desired.  One I saw discussed recently is that a Smart Phone when turned on
can be send codes to put it in eavesdropping mode where the phone is asking as a transmitter of what is said near it to a phone connection opened by the codes
sent to turn it on.
One workaround suggested in some discussions was to require everyone to remove the battery from their phone so there is no power for eavesdropping.  Obviously this won't work on an iPhone since the batteries are not removable.  Does the phone provide protection from having eavesdropping instructions from being sent to it?  Is there a way to temporarily disable the phone so it won't respond to such attempts?  If the phone is fully shut down (hold the button down until the turn off option appears and you slide the slide bar to turn it off.  Will it still respond to signals sent to it via the telephone connection or blue tooth link?  Is there a simple way to turn off that capability which allows the user to turn it back on easily when in possession of the phone?
There is a feature to disable receiving calls or messages during a period selected in settings where you give the start and stop of the do not disturb function.
However, I find Do Not Disturb sadly lacking.  If I go into  meeting for theater and am asked to silence my phone Do Not Disturb seems perfect for that need.  However the next morning when my coworkers ask why my phone is disabled, I have to admit I forgot to turn it back on.  What I really need is an option from the easy settings to disable no longer than 2 hours (length of the meeting, concern, movie, dinner party, etc.  then I do not need to remember to turn it back on.
If I set the start and stop time for the do not disturb option for now, if I don't remember to clear it, mu phone will re-enable at the right time but the next day it will go "dark" for the same interval even if I am free.  Was this feature ever tested using real people doing real life situations?  I found holes in the design and easy ways Apple could fix them.  But they keep ignoring my suggestions.
It seems if a feature idea did not come from the design team, the design team does not deign to read and evaluated decent ideas from customers.  I have talked with a number of long term iPhone users who would like such a feature.  I don't know if the competition is doing anything like it.

Answer 1

This is a user-to-user support forum. A good place for suggestions to Apple is https://www.apple.com/feedback/iphone.html