In back up manager there is an option to set up a daily back up - is this recommended ?
When you have just purchased the receiver and are still getting familiar with VIX and its settings, it is indeed a good idea to have it do daily setting backups. That enables you to restore a recentish backup if you mess something up and can't figure out what was the setting that caused problems.
When you reach the point where you have mostly found the settings you like, and don't change them much any more, you may be comfortable with less frequent backups.
I have my box set for weekly backups, and also auto-backup before image updates.
For full image backups, I use monthly interval. I see no point doing it more often.
Also, when there's a new image that requires fresh flash without settings restoration, it's a good idea to do both full image backup and settings backup, to make it easy to restore to the previous version.
Unpacking the settings backup file and examining it in a pc and comparing with settings from the new image may give useful hints on the settings and some other things.