Give it a hardening so that it has a resilient configuration. Allow only internal access from needed devices only. No security updates don’t means that your are affected from the next vulnerability

If your board (RTFM) has no pins/header for nic leds, you can’t use it. But if you have other unused led headers, use them to wire this (SAS controller, iSCI idle led on iSCI controller for example). often dedicated nic’s have this pins or real server boards with onboard nic. on consumer boards, i have seen this one time eons ago

I have placed my server in the cellar. Cost 0€ incredible effect for noise and cooling