Needs some ability to stop divinations from learning information about you, plus mind blank
Text of Improved Knight's Blade does not match table. And there are issues with granting an enhancement bonus based on class level - better to make it something that scales by HD, or just let you enchant yourself as a magic weapon a la the Ancestral RelicBoED
feat and have the effect extend to anything you wield.
Weapon Aptitude is primarily a warblade ability; IIRC bloodstorm blades gain it "as a warblade". In any case, warblade is easier to reference
Seems odd that it doesn't have Use Magic Device as a class skill or prereq; the capstone is also pretty meh, being essentially "your weapon gains a +1-equivalent enhancement, and you can use swords that harm an alignment your enemies don't have". You could just grant a bonus on UMD checks equal to your class level.