It is possible to create a user account from just CLI, but there is really not a reason to do it. as @Hugonaut suggested, I would just create the account with a policy. If you are going to do this with a script lookin in to salting (obfuscating) the password.
Are you creating the home directory? I dont see it in the script.
This is what I have used in the past. To be honest, I stopped using this a LONG time ago but may give you a point of references.
#!/usr/bin/env bash
AccountName="Some Account Name"
RealName="Some Users Name"
Password="For_the_love_of_god_obfuscate_this"
## Configure account
echo "Configuring account"
dscl . -create /Users/$AccountName
dscl . -create /Users/$AccountName UserShell /bin/bash
dscl . -create /Users/$AccountName RealName "$RealName"
dscl . -create /Users/$AccountName UniqueID "510"
dscl . -create /Users/$AccountName PrimaryGroupID 51
dscl . -create /Users/$AccountName NFSHomeDirectory /Users/Account
sleep 10
dscl . -passwd /Users/$AccountName "$Password"
dscl . -append /Groups/admin GroupMembership Account
createhomedir -c > /dev/null
## Add to SSH group
echo "Adding to SSH group"
sudo dseditgroup -o edit -a "$AccountName" -t user com.apple.access_ssh
## Create .ssh folder
echo "Configuring .ssh folder"
mkdir /Users/$AccountName/.ssh
chmod 755 /Users/$AccountName/.ssh
chown $AccountName:interactusers /Users/$AccountName/.ssh
## Set recursive permissions for folder
echo "Setting recursive folder owner:group to Account:interactusers"
chown -R $AccountName:interactusers /Users/$AccountName/.ssh/
