After the errors and important issues are solved, please consider changing the Default number of files to keep in the backup Folder to 20 or something, not 0 (no limit). If someone doesn't change this setting and does auto backups every day, their site could quickly exceed their quota disk space. Also, you might want to change the default number of Log files to 20 also. 50 seems a little high.
Also, when creating a new job, the default folder to backup to, is: .../wp-content/uploads/SiteName/. I suggest changing the SiteName subfolder to "/backwpup/SiteName/", so it's obvious what plugin created this sub-folder and what it's being used for.
Thanks. Hope to see an update soon.