Re: Aiki Ken and Ken justu
Well... I have been training Kendo - and that probably dosen't qualify me to fight somebody else in a sword - match. Neither does my aiki toho training (a form of iaido by Nishio sensei) or my training in ken-tai-ken.. At least not compared to somebody that have dedicated themselves to studying ken-jutsu in a style oriented towards sword fighting. However I'm pretty sure I will fare a lot better than someone with background in boxing, karate (which I also did for five years) or parachuting.
The answer is - as it always seems to be - neither a sounding yes or no. It's somewhere in between... Training with bokken or even iaito in combination with aikido practice will no doubt give you skills that would be useable in a sword fight, but if being able to slay someone in a sword fight is your end goal, then other paths are likely to get you there faster.
Just like if your goal is to kill people then it would be better to hone your skills in firearms than in swords...