I'd keep Righteous Zeal as it currently is due to it's presence in the Codex.
Abhor the Witch is too finicky. I like a rule that really pushes against any psykers in a soup containing BT or representing their intense suspicion. It may be easier to crib the rules for summary execution from commissars. Alternatively, remove it due to its overlap with the Vow of a very similar name.
Knights of Sigismund and Vows could be rolled into a single thing. I really think Vows, as the special BT thing, should be for BT only armies. You can have more power in the vows because of limited usage based on which Combat Doctrine is active. In addition, it opens up interesting unit, WLT, strat, relic options... especially if you like what I suggest next. Add two more vows, make each associated with a Combat Doctrine and then players choose which one they'll take for each Doctrine before a game starts. Then tweak the power of each vow appropriately. Personally, I think a weaker vow with no penalty is a better faction design option or tweak how the 'penalty' applies.
Devout Push - is the idea to use the pile-in to get into combat?
Massacre is a bit underwhelming. I get that it applies to the whole army, but the mechanics don't seem to live to a word like 'Massacre.' What about something like turning off ObSec (until end of next turn) on a unit that BT inflicted at least one casualty on? (And yes, I realize it's Red Rampage)
There is Only War - I get it, but it really defeats the purpose and intent of Combat Doctrines. Lower the CP cost, make it for a single unit. Or, keep the name and make it one of those 'choose a unit; it can re-roll a single hit roll and single wound roll this phase' strats.
Worthy of Dorn - "A fortification isn't cover if it's a castle!" Considering the relationship BT have to cover I recommend you make this about Overwatch. The BT unit with cover can use the Set to Defend option when using Overwatch even if the terrain does not have the Defensible keyword. If the terrain already has the Defensible keyword then the BT unit strikes first in combat.
Champion of Death - Needs to be bound to a unit or units; it's too powerful from a strategic perspective. Bind it to Marshells (Captains) and the Emperor's Champion and I think it's okay.
Duty Fulfilled - Split the effect in two. This one should be 0 CP and gain D3; have the other be something like "Cast Down Their Champions" and give the EC a -1 to enemy leadership aura.
Rip and Tear - Much memetic. I don't personally see the BT as savage and wouldn't include this, but for some there's not too much of a difference between savagery and ferocity.
Shield of Rage - Up the cost to 2 CP. Choose a BT unit within Engagement range of an enemy unit. Ignore modifiers on this unit from psychic powers.
The Last Wall - Fun 9,000 years ago, but not really an appropriate mechanic for the table top. If you really want to keep it then I recommend it be 1 CP, only last a turn, and only work on aura-generating unit at a time.
Crusaders of the Emperor - Too much. You currently have no strats about disembarking from a transport and charging. May I recommend that here.
Tactical Insertion - In the chain of causality it may be better to remove Guilliman from the blerb. Also, not sure what's tactical about a concussive teleportation flare or land raider crusaders launching grenades. Just call the strat Hammerfell Tactics and change the blerb to be about loud noises and bright lights.