Sorry, but this is a very very bad idea.
Trello is not only used by tech teams, but also by a lot of other kinds of teams with users not so familiar with technology.
Giving admin permission to all members of a team is a very bad idea.
Also, what about the unlike situation where a member is pissed of about something and starts messing up with the boards?
Please, reconsider it. At least, reconsider how it will be done.