Hello, @homme143,
Thanks for using our Theme.
1- In order to solve the issue please read the articles for a better reference to understand.
a. https://www.webroomtech.com/remove-password-strength-checker-wordpress-woocommerce/
Also, you can use this plugin for this purpose at your own risk: https://wordpress.org/plugins/wc-password-strength-settings/
2- I try to register on your site to check the issue and it is working fine, there is no issue. I created a user reset to the password to verify the email all is working fine. I made a video for you kindly watch it complete for a better reference: https://streamable.com/1p0drb
3- There is no WordPress name in the password change email please watch the video in point number 2.
Regards 8Themes Team.