Conversation - delete, archive, hide
Team Owner/Admin - possibility to delete conversation (old, improper, sensitive, ...)
Team Owner/Admin - merge conversation (users often start new conversation instead of reply to existing conversation)
Team Owner/Member/Host - add tags/category to conversation to be able to search in current channel by tags/category
Hide/Unhide conversation (channels with long list of conversation). Possibility to group/ungroup conversations by tags/category or date (month/year/chosen dates). It will be more readable for channels with excessive conversations.
Email conversation from channel (possibility to forward conversation via email - could be allowed/banned by team owner for members) or send it to other channel/team.