Last week I wrote about Grand Warlord Radha, a legend that certainly encourages more aggressive play
A: Wait 4-6 weeks
For decks with three or more colors, where you might only be able to afford a small number of MDFCs since you'll need most of your lands to either be basics (for ramping / tutoring purposes) or tap for multiple colors of mana, the best MDFCs are Bala Ged Recovery (seriously, if you have green mana in your deck, play this card), Valakut Awakening, Hagra Mauling, and Ondu Inversion, along with the mythic cycle, which is almost always good if you can afford another land that only taps for a single color of mana
Estrid's InvocationEstrid's Invocation seems to be tailor made for this deck
Teval, the Balanced Scale Teval, the Balanced Scale is a raw-power commander that gives you mill, land recursion, and a direct incentive to take cards out of your graveyard