I’m pretty surprised that all of the audio formats work. I’m no so surprised that the TV has h265, although maybe a bit surprised that it is exposed to the browser. The container support is also pretty surprising. Unless your MKVs are so simple that they are effectively WEBM.

Or maybe it pops the link out of the browser into a dedicated media player which has decent codec support.

iDevices do expose h265 in the browser, but the container support is still a bit surprising. But then again WEBM is basically MKV, so maybe that is why it tends to work.

There are a handful of common reasons.

1. The client doesn’t support the formats. Browser clients are notoriously picky not supporting some common video (for example few browsers support h265 and it isn’t generally considered web-safe) and audio formats. But embedded devices may also cause trouble if they don’t have enough CPU to do non-accelerated playback and don’t have hardware support for the codec used.
2. Playing at a lower bitrate. In that case you can transcode at the fly.
3. Remuxing. This is things like the moov atom where the actual codecs are supported but not the container or exact packaging of the file.

But yeah, especially if you are using a player with wide format support you may not need it.

IMHO for 2 drives you don’t want redundancy. (I assume that is what you want RAID for, mirroring?). The per-drive failure rate is so low that you are unlikely to encounter it and nothing you are running seems particularly availability sensitive. Having a bit of downtime to rebuild in the very rare case of a drive failure is fine. The extra storage space is way more valuable.

lol, I assume he means 1000 Mbps aka 1 Gbps which is reasonable. Maybe even a little low as transferring files around fast is nice.

IMHO this isn’t really worth it.

1. x264 is very fast at lower profiles. Especially if you aren’t streaming across the internet often the size hit from the fast profiles is fine. Even if you are streaming over the internet it is probably fine. Getting a slightly faster CPU will also get you super far and is more useful to have lying around than a GPU as it will benefit most things that you do on the server. And worst-worst case a bit of CPU usage isn’t going to hurt much of the things that he is running (except maybe a game server if people are playing at the same time and you are really maxing out all of your cores).
2. Integrated GPUs are fine for a handful of concurrent streams. Especially the Intel ones which have amazing media engines.
3. Even if you are going for a dedicated GPU I would go with an Intel ARC. They are way better at media encoding and cost less.
4. You can always add a GPU later. Wait until you have a need and are seeing problems without.