Your questions are entirely reasonable ones and you have posted in the right place.
I am using zfs on an ssd without that many snapshots and without raid. With NetBSD 11, it works very well. (With 10, it would have lockups.) It still allows multiple datasets within a pool, without needing a prior hard allocation. zfs in practice is boring in a good way. I don't have to do much about it, except run zpool scrub every month or so. It comes back after crashes, with no consistency problems. As for disk encryption, for external backup disks I use gpt, with a parition on which I do cgd and within that often another gpt and then UFS2. I set this up manually. I have the impression the installer supports more encryption than it used to and probably somebody will speak up. Even if it is still a manual install, if you're comfortable, can be done once and not be a huge big deal.
