I have some personal observations on this, and want to make clcear they are NOT based in anyway on personal knowledge of Saito Sensei, what motivates him, etc.
Listening to him/seeing him speak at seminars, the big take home message I get is his deep love and respect for O Sensei. Although his words are through interpreters, so I cannot say for sure, it seems like he is not a complex man, and I believe he lived his entire life around Iwama, not attending a university. Aikido and O Sensei were his life, from early adulthood onward. Iwama folks, feel free to set me straight.
That said, I interpret the fervor of his 'exactly as the founder taught me' statements in light of what I see as his background, as opposed to some of the other Shihan, especially those from the univeristies. So Edward, I don't see either his, or the similarly repeated statements of his students, to reflect disdain for mainline Aikikai, but just the statements of someone who has built everything in his life around his love for O Sensei and his belief in his version of Aikido, as he interpreted it to be from the founder. Not everyone is able to perceive others see the same things through different eyes, and I don't think that is necessarily a bad thing. When I listen to Saito Sensei, I hear true filial devotion, and that is a great example for us I think.
As for his weapons, he portrays them as how the Founder taught him. I never heard him say it was a way to win sword battles. Simply that it was what O Sensei taught him, so in his love for that man he now teaches us. Because the founder thought it was important to show him, he feels it is important to show us.