Slaughter Pact can be a good choice, especially with Dark Confident, but the no black creature clause can really be a set back (as is the no artifact creature that comes with Go for the Throat). What you expect to play will change those few slots. I would default to Path to Exile if uncertain.
Is anyone still playing GB? Played in a PPTQ today, lost to Titanshift in both swiss and quarters. I played 3/1 GQ/Tec edge split with just a single surgical in the SB. Might try 4 Tec edge and 2 Surgicals, though I suspect the matchup is just bad regardless.
Ghost Quarter or Tectonic Edge has been a decision I have struggled with for a while. I have concluded that Tectonic Edge is often the better choice because it does not give the opponent a land in return when I am down a land (similar to the discussions regarding Path to Exile). And though you are not able to act until the fourth land hits the field, generally that means that the opponent may able to deploy a single threat (Karn Liberated or Wurmcoil Engine) and that threat can usually be dealt with accordingly. In matches against decks like Titanshift and control decks, depriving them of that single land can make a big difference in how the game plays out.
As far as the one or two slots for removal, I alternate between Go for the Throat and Slaughter Pact in the main. Maelstrom Pulse is really the catch all card that more than pulls its weight, which is why I always have two in the main and now run in the side.