LMS on a Raspberry Pi (DietPi): Setup help

I started running into issues with my longtime LMS install on a ReadyNAS and decided to (finally) migrate it to my Raspberry Pi, which is running the current version of DietPi.

Unfortunately, I'm a bit lost when it comes to setup, mostly because the music shares still live on the ReadyNAS.

I started looking around for tutorials and blog posts that would walk me through some of the command-line steps, but I came across different suggested methods and didn't want to screw things up. The closest I came was this post in German — while I do speak the language, some of the additional qualifiers (e.g., "x-systemd.requires=network-online.target") weren't clear to me.

1. First, how do I update to the latest 8.3 nightly via the command line? DietPi selected 8.2 for the auto-install. On the NAS, I used to upload the .deb via the GUI, but that's clearly not going to work here.

2. On the Pi, how do I (auto?) mount the music shares that are hosted on the NAS?

• The NAS offers both FTP and SMB. I'd prefer to mount via SMB, but I think that might require installing additional CIFS libraries?
• The Pi runs 24-7 but the NAS powers off between midnight and 6am. Is that likely to cause problems with the mount?
• For security's sake, I'd like the share to be read-only unless LMS requires read/write access.
• Also for security's sake, I'd like to avoid storing the NAS user login/password in plaintext.

Any help would be appreciated.