Removal/deletion/hide Cortana and Mixer

For the Cortana settings, you can try this:

• Open Settings.
• Scroll down to System.
• Click on Cortana settings.
• Highlight the button that says On and press A on your Xbox controller to change it to Off.
• You will be prompted to restart your Xbox One for the changes to take effect.

As for Mixer, if you are letting them play Offline and without internet, it shouldn't work if they try to load it to watch any streams. I agree with you though, I would prefer if Mixer were not placed on our dashboard tabs. I don't use it, but it's there
and we can't remove it. I do wish that we could remove it and customize our dashboard to things that we want to use. As far as I know, there is no way to remove or disable Mixer. If there is, hopefully another person can help out with this. But you should
be fine if the Xbox is offline, as you'd need internet to stream Mixer videos. If your child was able to watch Mixer, then it sounds like the Xbox was possibly hooked up to the internet, as it can't play without it. Good luck though and I hope this helps!

You can however go suggest it or see if it's been suggested and vote on it at https://xboxideas.uservoice.com/ and maybe in the future you'll have this option to hide
some tabs.

That site is down and it is now recommended that people submit/post their ideas here https://www.reddit.com/r/xboxinsiders/wiki/ideas.

Where a few fellow Ambassadors have posted some link as to blocking Cortana, I see you do not allow for online game play. In this case, just an idea, disconnect from the internet and neither should work. As far as Mixer, I am certain no internet connection
will cause it not to work. No internet, no streams. For Cortana, I am not too sure how it works as I have never used it before. I believe it needs an internet connection from what I have read up on it. I have not seen if it still operates with an offline mode
but most articles say it does not. Removing the internet connection should stop them from being used.

The option to remove them, as stated before, is not there. In the settings Cortana can be turned off. Mixer cannot be removed but needs an internet connection to work.

Hi

Unfortunately, you can't delete or hide the Mixer app but you should be able to control what your son watch via the parent setting. Do you have your son's account set a child's account? If not here
how https://support.xbox.com/en-US/xbox-one/security/add-family-member-on-xbox-one. If you do, you can:

1. Log in to the console with an account that is an admin in your child's family
   
2. Press the Xbox button and then navigate to the right until you reach the System tab.
   
3. Select Settings
   
4. From within settings got to Account->Family and select you child's account
   
5. Select "Access to content"
   

Now you can turn off Cortana. Press the Xbox button to open
the guide. Select Settings > All settings. Select System > Cortana settings. In the window on the right, highlight the On switch, and press the A button to turn
it to Off.

It seems your other questions have been answered but for Mixer it's currently not possible to hide that tab. You can however go suggest it or see if it's been suggested and vote on it at https://xboxideas.uservoice.com/ and
maybe in the future you'll have this option to hide some tabs.