So, I have some ideas for some unusual interactions between subsystems upon Bladecraft. Mostly regarding having Bladecraft as a component of what other subsystems do.
In the case of spells, the spell could use a Bladecraft technique for a somatic component, allowing for that particular spell to be cast in the same action as that particular technique, and Silent Spell allows the spell to be used without the associated technique.
The second, obviously, is Maneuvers that require the use of Techniques as part of their use. The sword-swing of the Technique is the sword-swing of the Maneuver. This means careful selection of linked effects to make it not entirely broken, mind you. The idea would be a few Disciplines that draw from bundles of Styles for Techniques to stack Maneuvers on top of.
An example of a somatic Bladecraft spell is having a Vampiric "Strike" that deals 1d6, max 20d6, damage per CL, with the iconic temp HP equal to damage dealt, using a Technique like Black Lance's Last Strike(lower complexity implementation of the concept of backlash-by-counterattack, obviously), possibly with one of the Blood Style double-techniques so that the temp HP can be there before the backlash, as the somatic component. However, it's a 6th level spell(4th for Duskblades), which leaves it wildly underpowered for a spell of that level. But it functionally gives an extra Standard Action, of a particularly useful sort.
An example of a Bladecraft Discipline is using Maneuvers to specifically counter downsides for Techniques from many Styles that fit together as "risky" styles, like Black Lance's Last Strike being paired with a Maneuver that gives temp HP, delayed damage pool or other damage mitigation to be much more likely to survive the counterattack. The limits on use of Maneuvers make it so that it's not going to be spammed to cover weaknesses every time a Technique with a significant downside is used, unless you like burning rounds on Adaptive Style.
A more grounded idea is a set of Styles based on IRL airplane design philosophies. High-altitude bombers striking from unassailable positions, the SR-71 Blackbird's silly "outrun enemy attacks" spyplane strategy, the rushing impact of dive-bombers and frantic agile-yet-(relatively)-slow dogfighters make for the four "easy" idea options. I'd put the Blackbird-based one at Advanced because... Well, the idea is to never be hit because the enemy is never in range, always working to get close enough to hit. This is "move 15-20 ft. as an Immediate Action" territory. Not quite silly enough in mechanical implementation to warrant Master use, but not something you want to make casual use of.
...Is it inherently against the rules to make a Style that goes the whole way through? Because that'd give a significant amount of room to extend the existing Styles forward and backward. Extending Blood Style backwards to include much more basic Techniques that just give partially variable granted tags or minor improvements to other Techniques, like one extra Bladecraft die or giving a minor AC bonus/minor Moral penalty to the enemy.