I have an option in User->Options Button->set hook "Show Email Adress for other users"
It is possible have this as standart selected option?
There is no config setting for this. You would have to write a plugin to hook UserModel_BeforeInsertUser. That would be the clean way.
A more hackish way would be to change the default value for the user table:
ALTER TABLE `GDN_User` CHANGE `ShowEmail` `ShowEmail` TINYINT( 4 ) NOT NULL DEFAULT '1'
Not sure if that would do the trick but I think so...