Powerloss might happen as I don’t have a ups.
And when it comes to mdadm, it just happens to be the first and only redundancy tool I know. I am however open to learn and try new things.
ZFS seems interesting, but: I read that ZFS would require quite a lot of RAM, and I was going for 32 GBs only, would it be enough?
Could you elaborate on btrfs on top of md raid?
This one seems the most likely solution for me.