1. well in back end of custom registration we are running buddypress and buddypress does not provide such option to hold registration for approval .So as of now this is not available .Please create a feature request for this in feature request forums .
2. yup as of now it remains in fields .In next update we will be adding fix for this to clear the data .
3. Well Instructor profile field group does not shows to the users . you need to put "****" in your wp-admin -> wplms -> buddypress -> instructor profile field group to disable this :
http://prntscr.com/eefy08
instructor profile : i created some custom fields the problem that created custom fields not show in public profile and i already set put everyone option and <label for="allow-custom-visibility-disabled">Enforce field visibility so still did not show the information on public so how to fix this
</label>
so i will show for all user know ? student and instructors because i need separate custom field for each user so how to do this? because user registration is very important so i need quick support otherwise i loosed my registration