I think you should add a way were a admin or owner can be able to add and disable permissions from members like taking away the permission to delete cards other than there own that will make community's more able to really interact with the members.
Thanks for your suggestion!
In a Premium Workspace, we offer the ability for a board admin or a Workspace admin the ability to transition a board member to an Observer role, a read-only role on a Trello board. This would help prevent Observers from deleting cards and making other changes on the board where they're an Observer.
I'll share your feedback for other fine-tuned permissions with our team for consideration!