Hi
1. Issue: Registration page styling
Please paste the below custom css code to
Wp-admin > Appearance > Customizer > Custom css > save
legend{font-size:14px;font-weight:700;}
p#field-visibility-settings-toggle-1{display:none;}
Refer:
http://prntscr.com/ojg2nb
2. Issue: email sender address
Please try to revert back your changes in setting > general.
And to change the sender email address, paste the below custom css code to
WP-admin > Plugins > plugin editor > customizer.php > save
add_filter('wp_mail_from', 'new_mail_fromqw');
add_filter('wp_mail_from_name', 'new_mail_from_nameqw');
function new_mail_fromqw($old) {
return 'sitename.com';
}
function new_mail_from_nameqw($old) {
return 'site name';
}
3. Issue: Main page whitespace
I have checked and did not found the issue, please check this video I made for that:
http://somup.com/cqiZIBeXDg
4. Issue: Maintainance mode
Please use third party plugin for this.
https://wordpress.org/plugins/wp-maintenance-mode/