For the purposes of this guide, stick with Gonti, Canny Acquisitor as your commander
In order to use Mox Opal for mana, you have to have two more Artifacts in play
For efficient creature-focused answers, Go for the Throat and Infernal Grasp both offer clean two-mana removal, though with minor restrictions
Llanowar Elves is another strong reprint that could definitely usher in some powerful Green stompy or Gruul monster-esque decks, but I'd feel wary about playing that kind of strategy with so many Cut Downs and Go for the Throats running around in the format
In addition to these new commanders, Wizards of the Coast has also introduced a new mechanic called "Partner" in Commander 2016, which allows players the ability to have two commanders if both have the "Partner" mechanic, as seen below with two cards from the "Invent Superiority" deck
An early Sol Ring can completely warp the course of a game