Quick Study is really great, it allows you to keep up mana for your interaction and then draw cards instead if nothing comes up. Opportunity is the same effect as Tidings, but it's an instant. Reins of Power also have a similar effect to Cultural Exchange, but is an instant, so it can double as surprise blockers, a fog effect, removal (blocking with another player's creatures to trade), or simply to get value from other player's value creatures. Trail of Evidence can provide card advantage late game when you need to dig for answers or to sink your mana into. Perilous Research is another instant speed draw two that your commander offsets the downside to, which would allow you to dig for answers and keep up more mana to play those answers in the late game. Also, any card that has "Thirst for" in the name is good in these kinds of decks. I'm not sure if all of these suggestions go together in this deck, but I figured I'd throw them out there for some thought!