Hello,
1) I don’t know what you got yesterday but I tried a few hours ago and it was empty.
So, would recommend you to create all the templates you need and save changes. Let me know if you can’t save your changes or don’t get emails once you save your changes.
2) Are you talking about Appearance > Customizer? Then disable the WP-Optimize – Clean, Compress, Cache plugin and try again. It works once plugin is disabled or if Page cache option is disabled.
Or what customizer are you talking about? Provide screenshot, please.
Regards