This "/storage" mount point is a good idea. I do something different: I have
a /home/library directory, where I put all my books, musics and movies,
sorted not by file type, but in categories like "art", "politics",
"computing" and so on. In my user directory I have "office" things, like
e-mails, temporary downloads etc.
Note that the number of primary partitions is limited to 4 (or 3 primary and
1 extended), so you should make at least one of the partitions extended.
That's true if you are using MBR, but not if you are using GPT, which is much
better. Quoting myself
[https://trisquel.info/en/forum/full-disk-encryption-multiple-partitions#comment-15548
here]:
1. You could use GPT instead of MBR; an advantage is that you don't need
extended partitions, another is the CRC32 integrity-check mechanism; see:
[https://duckduckgo.com/GUID_Partition_Table]
[https://wiki.archlinux.org/index.php/GUID_Partition_Table] (Trisquel has
gdisk and GRUB 2 in its repos)
