Can I add my own messages to Operator? I can’t find any way to change the messages that automatically pop up.

Operator’s messages and texts are fixed, meaning that you can’t customise them or add your own. If you want to create your own unique bot flow, you can make use of our Custom Bots add-on to create outbound Custom Bots (to ask your customers a question while they’re browsing) or inbound Custom Bots (to help direct your customers when they start a conversation with you).