Did Isaac know he was blessing Jacob?

What does this text indicate about Esau's character? Jacobs?

Why did Isaac ask Esau to go get him a meal before blessing him?

Rashi on Genesis 27:1
ותכהין HIS EYES WERE DIM through the smoke raised by these women in offering incense to idols (Midrash Tanchuma, Toldot 8). Another explanation is: When Isaac was bound upon the altar and his father was about to slay him, at that very moment the heavens opened, the ministering angels saw it and wept, and their tears flowed and fell upon Isaac’s eyes which thus became dim (Genesis Rabbah 65:5). Another explanation is: They became dim just in order that Jacob might receive the blessings (Genesis Rabbah 65:8).

Sefer HaAgadah, 60.
"And his eyes were dim from seeing" (Gen 27:1). R. Eliezer ben Azaria taught: From seeing the evil deeds of wicked Esau. For the Holy One said: Shall Isaac go out into the marketplace and hear people say, "This that scoundrel's father"? I shall therefore dim Isaac's eyes so that he will stay home (Gen. Rabbah 63:10).
Or the phrase "from seeing" is to be explained by the tale of a distinguished man who had a beautiful and well-appointed reception room, next to which the neighbors used to burn stubble and staw, sending smoke in through the window. The man felt constrained to seal the window. Likewise, while Esau's wives worshipped idols, Isaac saw them and was so greatly distressed that at once his eyes grew dim-- [his "windows" had to be sealed].
Or: "From seeing"-- from the effect of what he saw at his binding. When our father Abraham bound his son upon the altar, the ministering angels wept and tears dropped from their eyes into Isaac's eyes, leaving their mark upon them. And when he grew old, his eyes grew dim (Gen. Rabbah 65:10, Midrash Avkir).

Daat Zkenim on Genesis 27:1
ותכהינן עיניו מראות, “his eyes had become weak from seeing (too much).” One opinion cites Exodus 23,8 where the Torah tells us that accepting a bribe corrupts, i.e. blinds the eyes of even normally honest judges. Yitzchok accepting venison hunted by his son Esau, caused him to overlook the numerous shortcomings of his son Esau without rebuking him. An alternate explanation of the word: מראות, “from seeing.” G–d weakened his eyesight in order to enable Yaakov to secure Esau’s blessing for himself. This is presumably the reason why Rashi wrote that his eyesight became impaired from the smoke rising from the animals offered as sacrifices to a variety of idols. (Tanchuma, 8)

Why does Rebecca get involved?
Why does Jacob go along with the plan?
How much did Isaac really know?

Was Isaac deceived?
What textual evidence demonstrates that Isaac was decieved?
What textual evidence demonstrates that he was not?

Sefer HaAgadah, 66
That wicked Esau... said "Let my father arise and eat." all but saying, "He's better" [in a curt and peremptory tone]. At that moment, Isaac recognized Esau's voice and, seized with fear, asked Esau "Who are you?" For when Jacob had come in, the fragrance of the Garden of Eden, a sweet savor, came in with them, and Isaac, feeling refreshed, exclaimed, "See the smell of my son is as the smell of the field [of Eden] which the Lord hath blessed" (Gen 27:27), as he proceeded to bless him. But when Esau came in, Genhenna gaped wide before Isaac, so that "Isaac was seized with great terror" (Gen 27:33). Perturbed in his heart, he said to himself: I see Genenna with Esau's body kindling the fire therein: "Who is the one who roasted in it? None other than the hunter [Esau] who has himself become game (Tanchuma, Toldot, 11).

The moment Isaac heard his son mention God's name (27:20) he knew it was Jacob, and not Esau. [Midrash] - Torah: A Modern Commentary, Plaut. 189.

Tur HaAroch, Genesis 27:1
Rabbi Joseph Kimchi does not believe that Yitzchok ever had the intention of bestowing on Esau the blessing of Avraham [which carried with it the power to bless or to curse effectively, Ed.] He did not feel that Yaakov needed a blessing, seeing that he was a righteous individual in his own right. He felt that Esau was in need of a blessing precisely because he was a wicked individual. He hoped that by providing Esau with the opportunity of pleasing his father by bringing him venison to eat, the pleasure he would experience eating it would restore a measure of Holy Spirit to him, something that had been lacking in his life of late. Even the prophet Elisha had suffered from the absence of such Holy Spirit until it had been restored to him as a result of the music played for him, something that relieved his mental depression. [in both cases the mental depression had been brought on by the person’s failure to see his words of benevolent instruction take root in the listener. Ed.] (Kings II 3,15)

Rabbi Norman Cohen in Self, Struggle & Change
If Isaac did recognize Jacob, why then is he pictured as asking his son a series of repetitive questions about his identity? “Who are you, my son?” “Come closer that I may feel you, my son—whether you are really my son Esau or not!” “Are you really my son Esau?” These piercing questions have another purpose. When Isaac asks Jacob, “Mi ata beni” (Who are you, my son?), he is giving him the opportunity to acknowledge who he is and what he is doing, since the decision is already made as to who will receive the blessing. He is really asking, “What is your makeup?” “What is your essential nature?” “Are you Jacob or Esau, or both?”