Tasigur doesn't really do anything in this build, so I'd probably replace him with Gurmag Angler since you can't activate Tasigur.

Why is Tasigur in this deck? Tajic, Blade of the Legion would be better

I am not sure if I want tasigur or angler. My rational for tasigur is that he is cheaper to cast, but I haven't tested much yet.

take out tasigur our in zurgo

Since you state, "My goal is to use Boros burn staples with the added benefit of black," then I would strongly suggest you find a way to sneak in "Bump in the Night," or as some like to call it, the black Lava Spike. It's useful because even though it's at Sorcery speed (like the other burn staples, Rift Bolt and Lava Spike), it causes loss of life as opposed to direct damage, which can sometimes be a relevant distinction, as life-loss cannot be prevented or redirected (unlike damage).

Drop one Swamp for Urborg, Tomb of Yawgmoth to help fix your mana base.

You might consider making this more like an Aristocrats build. I would recommend Doomed Traveler instead of the Angler. Sure the Angler is big but Traveler gives you more value, more things to sacrifice to Butcher of the Horde. Crackling Doom is something I would run in the Sideboard. You might like Thoughtseize or Inquisition of Kozilek. Also, if you can afford to get them, Bitterblossom is a good way to pump out more tokens every turn with no investment.

Sideboard tech? Sanctimony is a solid way to help outlast Burn strategies. Celestial Purge is a good option for Jund matchups, as is Shattering Spree to deal with Tron.