Howling Mine is a good way to make people draw without giving them any other bonuses (like being able to drop extra land). Sorin Markov would also help with his last ability.

Price of Knowledge could be fun too. If you can't get them to deck themselves from draw, then they can just gouge their own eyes out from having such a huge hand.

I would love to run Price of Knowledge, but it isn't Modern legal. I went with Rites of Flourishing instead of Howling Mine because I need mana to combo off. I don't know about Sorin Markov. I never really thought about using him. I may replace Mindslaver with him. It depends on which one would be better for me.

Dictate of Kruphix is pretty sweet, as well as... Remand and Arcane Denial; which are good for keeping cards in yours and your opponents' hands.

Oh I think I have a perfect one for you, how about Jace's Archivist so that when your opponent has like 18 cards in their hand from playing their stuff you can make that another 18 down the drain. (:

I know that you decided on rites of flourishing but you could also go for Font of Mythos

Probably you will not want this guy but Fate Unraveler

Or how about Waste Not

I think that a white splash is better; Supreme Verdict, Path to Exile, Idyllic Tutor and plenty of white fogs make it superior. Plus white has the best sideboard options.