1) Option for new users to be subscribed by default; 2) Batch add subscriptions for multiple users (per username or role)

Sorry for the critical state of this feature request, but i think the module needs this features really bad.

1) There should be an option to pre-subscribe new users no certain subscrptions.

This is especially necesarry for corporate use cases.

I know that there are already some ways to let new users choose subscriptions during registration. But in my intranet site user registration is disabled and new users are created by LDAP Auth module.

Site admins should be able to subscribe other users to notifications.

Notifications module has a brilliat site-wide interface to administer subscriptions of all users. It copies the Drupal's native content administration interface.

It lets you view, edit and delete subscritions. Wait, where's the ability to add subscriptions?

I wish there were a way to subscribe users to certain notifications — by typing usernames (with autocompletion) and/or by selecting roles (with checkboxes).

There is already a powerful interface for adding subscriptions in Notifications UI, why not use it for this purpose too?

 
There is a Custom Subscriptions module (bundled with Notifications Add-ons) that provides a workaround for both requests, but it's a bad solution. The problem is that Custom Subscriptions and Content Notifications don't know about each other. Custom Subscriptions' subscriptions will appear as unchecked in Content Notifications and vice versa.