Frankly, it looks like you're getting bent all out of shape because you made up your mind about this before you even made your OP, and are now finding that next to noone agrees with you.
I don't see why they should get anything like Blademaster either. One paragraph from some fluff is a bull reason to be handing them talents or whatever, I don't care if it's from their most important book ever. You don't see Black Templars getting Tactics (Void) for free, but they all live on a starships (maybe if they had T-Pain there to cheer them on). Give them the option of taking a ceremonial sword, like the Dark Angels, and they're fine.
Cause hardon for duelling doesn't really translate in to a commesurate battlefield proficiency with the blade.
Let's run this through point-by-point.
I said before that I could live with it even if that was not my preferred solution. Even just giving the IF such a trapping draws some attention to their honour duels and honouring the sword.