Okay I am looking at the wiki now and realize a lot of the changes being made are to ensure your system stays up and reliable.
The step you mention (sudo passwd -d root) will remove the root password. This sounds unsafe however there are policies in place to prevent access to a root account without a password. As a result, the only way to access superuser privileges is to sudo. Essentially, this is a security measure.
The tempfs is used to prevent logs from writing to your SD card. This increases the lifespan of the memory card but sacrifices log files after a reboot or loss of power. These can be helpful for debugging problems however on a stable system it probably is ideal to remove stress from the SD card.