I cannot imagine playing this deck without Steppe, Ghost Quarter, or Bog. My thoughts:
Against the fast combo decks, Bog can mess up Dredge, Storm, and Reanimator. Otherwise, our only interaction with these decks is Discard + Needles, and Needle isn't very effective against those decks.
Against Wasteland decks, having Crop Rot -> Ghost Quarter is quite nice because you don't need additional mana to disrupt their Wasteland, meaning you need only Stage + 2 mana + Crop Rot mana instead of double stage activation or something.
Against all sorts of decks, Steppe wins games. StP decks are embarrassing to play against if you don't have Crop Rot -> Steppe or Sylvan Safekeeper / Not of This World. I cannot imagine playing against an StP deck with your version, so D+T, Miracles, and the various Stoneblade versions seem very hard. Besides StP decks, you need Steppe to get through other Marit Lages, Delver chump blocks when they have lethal damage on crackback, Strix chump blocks when they're going to use Lily or Jace to kill Lage, Cavern Harpy blocks when you don't have Needle against Aluren...
Against Lands, not having GQ, Steppe, or Bog makes the matchup unwinnable. Without GQ you can't kill a Glacial Chasm without exposing yourself to Wasteland/GQ. It can be very awkward to play this matchup (or the mirror) without Steppe, even with Karakas side because you might need to Needle it, because you don't have a GQ. Without Bog, you don't have a way to shut off Loam engines that beat us.
These three *tutorable* answers are a must. I understand that you have ways to disrupt some of these things otherwise, with Needle or removal or multiple Stage activations, especially considering you have Stirrings to find Needle. However, in my experience I have *needed* these three effects. Not having Bog swings the Reanimator matchup from favorable to probably not favorable(?). Other effects are less noticeable but they contribute to win percentages across the board.

