Is there any way to re-map the menu button or use the Xbox app

You can use the Xbox Accessories app to re map the buttons.

Hello Dan203,

You can map buttons to be "unmapped" or "disabled" using the latest version of the Xbox Accessories App (on Windows 10 and the New Xbox One Experience).

To accomplish this, launch the App, press the "Configure" button below the image of your controller, select either the configuration in the slot you want to change or make a new one, go to "Button Mapping", select the button you want to map to "unmapped,
and then in the menu below "Map to (button)", go to the bottom of the list and select "Unmapped".

I hope this helps!

Quit the app by using the menu button. Then re-open the app, should work then. It is true, this is just registering for the beta, not the update itself.

Are you referring to the apps on the Home tab or the Pins tab? To pin Internet Explorer, go to your My Games & Apps section, click the Menu button (the old Start button) and click Pin to Home. Any pinned apps will show on the Pins tab. To unpin an app, go
to the Pins tab, highlight that item, click the Menu button and select Unpin. The apps on the Home tab is more less recent history. On the Pins tab, the only re-arranging you can do (without un-pinning and re-pinning )is using the Move to Front option, which
will put the Front app in the upper right-hand corner. Probably the easiest way to do this is to create a list of the pinned apps you want (most important at the top, least important at the bottom), then using that list and going from bottom to top click each
app and select move to front. Once you are done the last one you Move to Front will be the top on on your list. Hope this helps!

The same way as any other.

Manage games & Apps, menu button over the app and select uninstall.

Some apps though can't be uninstalled.