You can't search member in a group  you can delete your message that has been delivered and the after you delete  the receiver can't read that message. If you want to add new contact  you must know the number. That make difficult if you want to make a group. because when you want to make a group  you must at least have one person. And if you want to make a group that will be filled by a new person whom you don't know  it will make complicated
February 07 2017