First would be a temporary option during Open Beta that allows friends to link to accounts. I am not sure if that was even an option for the CBT, but many of us brought friends into the experience, it would be nice to get those rewards.
Second suggestions is a limited trade option between the linked friends without the need for premium. I can't say what the limits should be, but I am confident there is a good middle ground. This could be tested and if it gets abused just remove it and make an example of the perpetrators. (I hear HWID bans make cheaters sad)