This makes sense

No sense in getting rid of hardware that is working. I’m not familiar with ersatztv but for all the other stuff I am able to handily run it on a 10th gen intel build that is also handling nas duties fwiw. And some stuff is not ideal (cctv is handled via blue iris, which runs in windows VM, everything else is docker)

for the gpu it really depends on your needs. How many users is the big one. If you have at most 2-4 concurrent users and that is an uncommon scenario the gpu is a waste of power, money, and thermal management. Igpu will sip power and transcode (depending on library content, again av1/vp9 on a 10th gen isn’t happening) with that user load assuming you have a decent amount of ram (I have 32gb so you don’t need absurd amounts).

However if you have a lot of users hitting you, 5-6+ or more concurrent streams that all transcode, then you need to start evaluating a discrete gpu (and maybe a significant internet connection bc damn). Alternatively you can suggest your users get something like a ugoos am6b+ flashed with coreelec or a similar setup that can just direct play basically anything but that’s a bit challenging to setup

So then it may be as simple as buying some e waste pc to use a server and using the nas as its intended purpose. Frankly this is probably better, it’s worse power wise but having the storage separate from services has advantages