Hey Big Jon,
whats going on over at tanith? I've not been able to get on it for ages?
Aaannywayyyyy.....i like your point about what Iwata sensei said. I was there buddy, at one of his seminars in Leeds when he proclaimed his intention to rename the art. My sensei in iai and aikijujutsu is one of Iwata sensei's favourite gaijin and he's an excellent mentor and friend...at 72 years young.
As regards the OP, i think its daft, irresponsible and dangerous to start off with shinken. Soldiers don't get given a live weapon as soon as they join the army. Why would some n00b be given a 3ft razor when they first step into a dojo and learn how to hold a sword?
They very fact that someone is taking up iai should point towards them being of a certain nature and holding respect for both sword and art itself. You don't often get wannabe's trying out iai, because they want "to cut sh*t up!"
Progressive training is the way, as it is with all MA's. Currently at shodan level in kendo i don't expect to understand or be taught yondan-waza yet.
Much the same for a yellow belt in karate wouldn't expect to be shown black belt techniques.
Seeing as the OP mentioned aikido. It took me 10 years to reach my shodan through progressive 'experience', a lot of this was off the tatami whilst injured. But when i came back, my aikido and my spirit were so much stronger and better for it.
Iai is the hardest MA i've ever studied, mentally its so draining. IMHO, bokuto > iaito > shinken (maybe)
I do, however believe than tameshigiri is an integral part of senior practice. It will certainly test your cuts in the truest form.
Bear in mind also that iaito are a lot lighter than shinken so adjustment traning would be needed as well.
I've skewered myself once with my iaito, but not yet with the shinken. Just about everyone i know has sliced the webbing of their left hands at one stage or another.
"A man should never have sexual intercourse with another man. God hates that!" Leviticus 18.