While the list can certainly be set up in Google, no links to a Google doc can be posted here. If you want to post the list, you need to convert it to a picture and then just post the picture (either directly on the Cruise Meet thread, or in a conversation).
As the originator of the conversation, when you open the conversation, scroll down and all the way down on the right side is "Conversation Participants", at the bottom of that is "Invite more". I'm not sure about how to delete participants, but, maybe, if there's more than 2 participants there's also a "Delete" link? All the conversations I've been involved in thus far were only with 2 participants. Sorry.