I think it's possible to act honorably without opening yourself to be betrayed, so I don't think the Almighty wanted Dalinar to trust Sadeas.
Yeah, I understand that -but the main thing that might have been important there is that he acted honorably to Sadeas - I think trusting him was just a misunderstanding of the message on his part.
I took it as definately an effectively recorded message after the last vision.
Well, it was a vision sent by a deity - it was flexible - he could interact with people in it and change things that happened in the vision (though I
highly doubt anything is
actually being changed in the past), and the deity in question, while tending to repeat himself, DID respond to prompts, but simply said 'I can't tell you any more' in most cases - perhaps because it was still ultimately a message and a message can't give more information than it has been given.
Also, 'fraid I disagree with it being all about attracting an honourspren, the conversation with Nohadon in one of the visions implies that there are other sorts of spren which can give ppowers other than honourspren. "not all spren are as discerning as honourspren".
As for the most important words a man can say? Maybe "I will protect those who cannot protect themselves." or perhaps "Life before death, strength before weakness, journey before destination."
Yeah, those words are the oaths of the Radiants, which when spoken to an Honorspren gave Kaladin his full abilities. The fact that Syl was constantly going "say the Words! quickly! say the Words!" implied that saying those words had some extra meaning which further empowered Kaladin's bond with Syl.
And even though there are other spren capable of giving power, it might still mean that Dalinar is one who could gain an Honorspren - it
does fit his personality perfectly. Even though Kaladin got one first, Kaladin and Dalinar are together now so they might both, together, end up recreating the 'honorspren' branch of the Knights Radiant