In the event that a particular strategy that fully relies on one or more of these mechanics, Grafdiggers Cage will be the go-to answer
While none of these lands are Forbidden Orchard, you get a couple of Magic 2010 buddy lands, a couple of pain lands, and a couple of tri-lands, most of which are a worth couple of dollars, and these cards have already been reprinted into the ground, so its unlikely that they drop too far based on the increased supply from Commander 2016
Tocasias Welcome is my current pick, for a couple reasons mainly that it triggers off of tokens, and because it triggers on opponents turns, and because enchantments tend to stick around longer than creatures
Mai and Zuko Flash enablers are always useful, but Id rather have Leyline of Anticipation in the deck and reserve the command zone for something more immediately impactful than Mai and Zuko
The first ability on Chandra, Torch of Defiance, on the other hand, says: Exile the top card of your library