Pls note the command executed in linux terminal will be kept in history file, therefore your passphrase maybe at risk. If you want to keep your passphrase out of bash command history, add ; history -d $((HISTCMD-1)) into your command line, so the 2nd command in step 8 should be:
./pivx-cli walletpassphrase [YOUR PASSPHRASE] 999999999 true; history -d $((HISTCMD-1))