If you're planning on publishing games in traditional channels, I'd recommend making sure your licensing is in order. I think there are some free resources in the marketplace, but otherwise, I highly recommend paying for what you need.
I have Jellyseerr set up so that I and my friends can request things that will automatically get pulled down. It also has trending and upcoming content, so I sometimes find stuff there. Also, generally, I just see/hear people talking about stuff and want to check it out.
I had 2TB of space when I got my NAS, and that was more than enough for my lab, until I started downloading media. Then I bumped it to 4TB and then recently 12TB.
I want to have content for myself and my users. I will occasionally delete things if I don't think anyone else will want to watch it and I won't want to rewatch it. That's usually nothingy action flicks.
Use night - it's by far the cheapest I've found (20 euro for a year). Gives you fast speeds at night and throttles during the day. Not an issue for me.
Does it matter for TV?