Some Weapons already Got a Element from the start and that´s a clear advantage. Are you allowed to use it or why is it not in the rule work

The weapons that have elements already attached to them are available to everyone. Yes it is behind a paywall and you must spend money on them, but it is not an exclusive item that only select consoles/players can have. Because of this, the use of these weapons IS allowed. There will be a section added to the rules to indicate this.