My Opinion: Did Yitchak Know What He Was Doing?

We all talk about Yitzchak's intentions as far as the giving of the 3 brachos to Yaakov and Esav. We have come up with 3 options so far: Yitzcka planned on splitting the Bracha all along, Yitzchak was going to give it all to Esav, and Yitzchak was going to give it all to Yaakov. We have come up with different facts and aspects in class pointing to one or another of the three options above. We said that Yitzchak probably wasn't planning on giving it all to Esav because when Yitzchak blessed Yaakov thinking he was Esav, he didn't include anything about the spiritual aspect of the world or even mention HaShem. Yitzchak was a very spiritual person, so why would he ass on the full bracha to one son and not mention HaShem or religion? We also seem to think that Yitzchak was not planning on giving the whole bracha to Yaakov either because the torah says that he trembled a great trembling when he realized that it was Yaakov that he had given the bracha to instead of Esav. I think that Yitzchak really did plan on splitting the bracha between his two sons, but when Yaakov took Esav's place for the first part, Yitzchak realized that Yaakov really was capable of presiding over both parts: the spiritual and the political/social. Yitzchak then gave Esav his own bracha because after all, he was the elder son and Yitzchak's favorite (for better or for worse).