Preventing players from using life to cast spells or activate non-mana abilities is likely to become more relevant in Standard as The Brothers War, Phyrexia: All Will Be One, and March of the Machine release
You will be hard-pressed to find a no-downside, straight up destroy effect for enchantments in red
No multicolor mana costs, and no artifacts with a red color identity
Mana Confluence seems due for a spike, and Id make sure to pull Insolent Neonate out of your bulk
Unless you had a Mage-Ring Network power play in mind when you designed this, getting Blue / Colorless supports out is not super useful at winning
In the case of Drix Assassin, you can use the 1W mode to remove a blocker temporarily, or exile a token, for instance