Thanks for looking. I think this deck does a good job of capitalizing on the intuitive card synergy between deathrattle/charge/taunt. The warrior specific cards can be useful as offensive or defensive board control maneuvers. The 0 attack minions double as damage absorption and a lukewarm stealth for deathrattle minion being produced. The legendaries are nicely placed, but not necessary for the deck to perform; although I haven't tried it without tbh.
Mulligan - keep anything 2 or under, except bolster. Sometimes, you may want to keep a fledgling or an igneous if going 2nd.
I'm still figuring out how to track statistics in a postable way, can someone recommend a good app?
Substitution guide for Legendaries:
Barnes - Barnes has an approximately 75% chance at producing a high value 1/1. He is not critical to any deck synergy, though. So, you may replace him with any deathrattle minion that produces a card or a minion. Shop around, look for something that works with the cult masters. Piloted Shredder.
Baron - The Baron allows you to double up on charge deathrattle minions any time past the fourth turn. I do not recommend replacing him with the other deathrattle doubling minion, Spiritsinger Umbra, because Umbra requires you to play the minion you wish to double after playing Umbra. With the Baron, you can double a minion that is on the board from a previous turn, so Umbra is just not a powerful enough replacement. Not to mention that Baron comes with 7 hp. Replace the Baron with another deathrattle minion that produces a card or a minion. Piloted Shredder.
Sylvanas - Sylvanas allows you to mind control when the opponent is producing large taunt (can't attack). I thought about replacing her with a single, mind control tech; I haven't tried it, but you might want to. If not, just replace with a deathrattle minion that produces a card or a minion. Piloted Shredder.
Kel - This is for a long winded game that gets to turn 10+. He will replenish your board with blank copies of your low cost chargers and summoned 4/4 (nerubian) and 5/5 (faceless) minions. This allows you to maintain board dominance after an attack that wipes your side. Once again, he is great to have, but can be replaced by any deathrattle minion that produces a card or minion. I do not recommend replacing him with the other legendary deathrattle minion, N'zoth, because N'zoth resummons previously killed deathrattles. This will just clutter your board with useless 0/2 and 0/3 minions that will not have charge or taunt. The opponent will have no reason to kill them, and you have very few options as well. You guessed it, Piloted Shredder.