First of all, congratulations on an incredible plugin.
The one error I found (and maybe I'm just missing something in the settings), is that for some reason all the notifications send from your plugin come from "firstname.lastname@example.org" (mydomain = the domain the plugin is on) - as such none of the notifications are ever delivered to recipients because they are viewed as SPAM by most email providers.
This is strange, because most plugins simply use the email address that is set in the General Settings page in WordPress to send email.
Is there any reason why your plugin doesn't use the General Settings email and instead uses "email@example.com"? Is there a way to change this?