Is there a way to add a second registration field for the user to confirm password to be sure they match?
If you have not deleted the default fields the plugin installs, then yes, there is a confirm password field included in the initial setup. You just need to enable it to display in the form.
Also control length or other requirements for passwords?
All text fields accept the HTML5 input pattern attribute, so it is possible to add a pattern for the password field.
If you want something more robust, there are action hooks that you could use to create a rules-based password requirement:
There are some tutorials on the premium support site that describe how to create a custom password rule. And the WP-Members Security extension includes a number of password options:
- Require random passwords to be changed on first use
- Require passwords to be changed after a defined period of time
- Require strong passwords using the WordPress password strength meter
- Require the current password when changing a password
- Require new password to not be one of previous X passwords used
