Pyrosis did a great job answering a lot of your questions, I will focus again on why I cannot recommend plex:
Opt-In is not acceptable. You need to opt-out of: data sharing, data sharing with partners (unless you are in the UK or specific States), sharing playback data, stopping discovery together and activity feed, and turning off all of their live tv and streaming services.
Sharing streaming habits with others is not something that ever should have been opt-out. They keep pushing the line.
By the way, several of the “features” you mention are not included by default. Hardware decoding, downloads, DVR, etc.
I have been using openmediavault for years and years. Basically debian with some configuration already done for a web gui, quick access to shares and user controls, and a simple but ready docker setup for your containers. Extremely light weight.
I have unraid on a test server, but I just can’t see the point of using it over omv. Raid is not important to me, you have to make backup either way. Containers are containers, and a vm is not something I need