Went 3-1 with the even more reviseder version of this deck and got second place! Technically it was 3-0-1 because the undefeated guy split with me, but he beat me for fun. Here are some matchup thoughts:

UW Control

I steamrolled this matchup. Can't Detention Sphere a Boros Charm. Also Toil/Trouble for 7 on turn 3 is AWESOME.

GR Monsters/Aggro

My toughest matchup. My only hope is stopping the mana ramp early and having an answer for Polukranos (aka Chained to Rocks) before it goes Monstrosity. Subbing in the Reckoners and subbing out Skullcracks works well here. Also Spark Trooper can put in some work.

Selesnya

I do okay against Selesnya, but not great. Its almost always a race, and Chained to the Rocks is my best friend here, as well.

Mono Black

I should do great in this matchup, but I don't. Maybe I'm a bad player. Can't race Desecration Demon, and unless I take care of a Rat right away, I'm also screwed. Subbing in Toil//Trouble helps a bit. Always keep a Skullcrack at the ready for Gary.