I need these users to be active without the manual intervention. Can I get some guidance?
Likely using database queries of Joomla API to add users, which neither will work. You'll need to use CB API. Please see the below tutorial regarding how to use CB API to create users.
www.allmysocials.com/directory/tutorials/item/237-create-users-through-api
I am running CB 1.4, and am unable to upgrade yet due to dependencies that I am concerned will be broken by the custom software.
Can't help you, sorry. We don't support core edits nor do we support archived releases. You need to upgrade and avoid editing the core. If installed CB plugins are the concern in most cases they'll continue to function perfectly fine; otherwise contact the developers for possible upgrades.