My try on a boros heroic deck

My first reactions to the build:

1) You're sitting on too many copies of legendary creatures.  You're going to end up with dead draw Anax and Cymede a air amount of the time.  Further, Heliod would be best as a 2x, as you don't want to dead draw one, especially since he's unlikely to actually become a creature given your current configuration.

2) Your creature count is quite low and manages to omit one of the best heoric creatures in the set, Fabled Hero.  Given the number of cards you've allocated to triggering heroic, you will likely have games where you only draw 1-2 creatures and a ton of pumps, only to see the creatures removed and you frustratingly drawing dead until they take you out.

3) You have a direct conflict of interest between Hammer of Purphoros and only having 20 lands.  Simply put, it will be highly unlikely that you're ever going to have enough land to really sack into more than 1-2 golems.

4) Spear of Heliod is good, but I wouldn't run any more than 2x of them.  If you're dying for more anthem effects, either more Legion's Initiatives or Path of Bravery will work.  The problem behind having just 3x spears is that you'll never have more than one anthem at your disposal care of its legendary status.

5) Tajic is good and I think there are places for him, but I can just see where you're seldom going to trigger his battalion and even then he'll just get chumped almost endlessly.

6) You'll really need at least 2x Sacred Foundry if you're planning on going to an FNM to really be competitive.

7) I'm seeing ZERO removal on your part.  R/W has a LOT of options to help deal with opposing threats.  Lightning Strike, Magma Jet, or even better given that you're playing with red, Chained to the Rocks.  You need at least a few options to deal with your opponent's creatures, otherwise, there are bigger and better creatures than you're using that will just overpower you.

I think to really make boros work you need to commit to either a full out aggro strategy or a more mid-range game.  Sadly, heroic has some promise, but I don't know that it's worth building an entire deck around just yet.  For an aggro build, you'll want Akroan Crusader, Soldier of the Pantheon, Rakdos Cackler, Firefist Striker, Daring Skyjek, Wojek Halberdiers, and things of that like.  For a mid-range build you'll likely want to culminate in Assemble the Legion which is just a monster card that ends games on its own (although it is actually outpaced by Elspeth until the 10th turn they would both be in play).

Ethereal Armour and Madcap Skills