Android for Work or Custom Rom? We are attempting to present our progressive web application inside android for our end users who are seniors and would like to have special requirements met that I am not sure which approach we should move forward with. Help from the community would be much appreciated!

We have developed a web application that we would like to run on top of in a sort of advanced kiosk mode on an android OS in a tablet device. Additionally we need to offer our users an interface to modify their wifi settings. These are our rough requirements and wonder if we can reach them using Android for Work or if the community has recommended solutions such as if a custom ROM is necessary: 


boot into kiosk mode
initial boot screen is branded or customizable
remove the android header bar
expose via our interface connectivity settings like wifi, bluetooth, and cellular data
access to the device camera 
access to power off function
access battery levels


My research into current EMM provider solutions on the market shows that these solutions can really do a lot with the Android OS with the Device Owner permission. We are testing one option now. I'm just not sure if this would be the right approach. Your help is appreciated.
You could try the Android Management API, it allows to manage a device the same way an EMM provider would do.