Re: Why these techniques?
The easiest way to think about the "why" of these techniques is to imagine you or your opponent as being armed with a blade.
still ridiculous... you don't need a weapon to justify... just the hand grab/strike is justification enough... the 'classic' waza ie Ikkyo, Nikkyo etc. are principles as well as techniques... consider them as specific techniques AND as drills that improve your body mechanics/feeling/awareness for martial situation... ever used ikkyo on the ground or kokyu nage or sankyo??? of course you have... although you may not have made the connection yet... look at the kimura... looks like an ude osae/ikkyo to me... Osensei showed us a book... you have to open it and read the fine print...