I am not sure your hate % numbers are making sense to me. I do not understand if the chimeras fang is different, but does not hate work similiarly to healing amp i.e. weapons do not stack with gear and similiar %s do not stack. I was just thinking about that VOD run we did and the way the hate worked in there with scain did not make sense to me.
You have the brawn's spirit 10% hate and the claw set 20% hate would not you want to drop greater mark of the sentenial for skill focus intimidate thus making it so e-fang is 15% hate and all three stack? As a nice bonus you would save enhancement points and your intimidate goes up +1. I already swapped a feat last night but was thinking that I should swap weapon proficiency khopesh for skill focus intimidate instead of greater dragonmark of the sentenial when my time period is up again.
Edit: I reread the descrption and 2 marks would just give 10% hate...hmm what a weird weapon.