Hey Brian 
I’m not sure I understand. When you tap the search icon it will redirect to the /search page so you can go back with the browser/mobile navigation or gesture.
Some update again… I’ve decided to not delete header icons, only hide it with CSS. Yesterday, when I fix the hamburger menu opening animation I figured out it will more easier, clean and safe I think because this way we can trigger the default header icons click. Now the hamburger, notification menu and search working this way. The default header chat icon is also just hidden with CSS because on /chat pages it will show on header.
I try to make the settings simple as possible.
It will contains 4 fields the descriptions are missing yet. Destination is optional because if you choose a function it will include the necessary thing and this field should leave empty.
Admins can simply create/remove/change tabs and select from one of the functions or add a custom destination to the tab.
Functions 
E.g. adding topic creation tab will simply looks like this.
