aio-switch-updater VS NxNandManager

Have you checked AIO? There is a good chance that FW its already there.

You can also grab it from their GitHub, you should be able to get some info there

put this on sd https://github.com/HamletDuFromage/aio-switch-updater update

Now as for the 2nd section you can just get the official firmware through AIO updater. After getting the OFW just follow the third section and you should be good to go.

Use AIO Updater

I believe https://github.com/eliboa/NxNandManager might work. But if your nand is corrupted, there might not be a way to get those files.

You could try to extract the saves from the emunand (if its not corrupted yet). You can use nxnandmanager tool (read their github on how to) OR follow this guide

Hmmmm. Take a look at this. It might be more useful than me.

From there download NxNandManager here https://github.com/eliboa/NxNandManager

Not automatically, no. You'd have to use something like JKSV on sysNAND CFW to export the saves and import them into emuNAND. Alternatively you can use NxNandManager, which is more complicated.

You should be able to, yes. The NxNandManager tool by eliboa has a feature where you can resize the USER partition of the input NAND. You'll need to dump your keyset using Lockpick_RCM so that NxNandManager can interact with the backup.

NxNandManager (https://github.com/eliboa/NxNandManager) and your switch's keys to decrypt save from user partition.