Samsung Galaxy S4 Active — S4 Active as Network Security Cam

Good evening.
I'm looking to re-purpose some S4 Active's as Network Security Cameras and have a few specific questions as I'm new to the custom ROM world for Android devices. I currently have a less than operable (but operable) proof of concept going, but ideally I'd like to trim some software fat and fine tune.

The goal is to network the camera via a USB Ethernet adapter while providing power via a viable POE solution (power splitter/joiner, 3rd party POE solution/adapter), running an IP webcam application that integrates with ZoneMinder, and managing the device (post initial configuration) via SSH. IP Webcam from the Play Store currently supports integration with ZoneMinder.

My ROM & device specific questions;
1. Is it possible to set runlevels' on any Android ROMs so that I only have a local shell login and SSH access?
I'd only want the device to power up to a shell, no GUI unless I change the runlevel.
2. Device charging and OTG use at the same time?
I'd like to connect a USB to Ethernet adapter for connectivity, while employing some type of POE solution to keep constant power delivery to the device.

— modified on Oct 30, 2016, 2:37:01 AM