1. GUIs can be (and have been) written for channel management and other functions. There's multiple clients (or client plugins) for such functions as changing modes (with checkboxes), changing the topic, etc.

2. ZNC has plugins for push messages, or at least it did when I was using it several years ago. My personal bouncer was configured to automatically set my away status when I went offline; alternatives include (de)voicing (in)active users, changing nickname, etc. When my bouncer had no clients connected and someone sent me a pm, it was configured to send a message to Pushbullet.

If you're not using a bouncer or the bouncer is down, services packages such as anope may include a memoserv for sending messages to offline users; on services login, memoserv will notify you of pending messages.