Like most Ninja stuff out there, take it with a grain of salt. All of those techniques with the grip are also in Chinese and European long sword systems.
I know
But I have to confess that as a Fantasy-RPG-addict I love to ponder about the possible ways to use a blade; that fascination also jumps from European long sword to naginata to rapier / small sword to this ninjato-thingy to ... more often than I'm willing to tell

As far as handling. I have found the heavy grades to give a very nice accurate balance. Katana and such are often balanced further up the blade than straight swords. But, if you are looking for the length, you can pretty much choose anything that you feel comfortable with.
Good to know.
I also found pictures of your 'Bride of Frankenstick' (the version with the Arbiter emitter); that's quite what I had in mind