Please report any issues at https://github.com/sean111/terrariahb/issues and include what phone and Android OS version.
The permissions are due to Phonegap. I do not read any phone information. If you want proof check the source code.
To go back a page use the back button on your phone
The menu key will take you to the main menu
The search key will take you to the search (also you can get here from the main menu)