Well you worded it terribly, do better next time. Aizen knew Gin would betray him, that isn't "having an idea", that is him literally knowing for a fact. I already told you, Aizen does not need to see something with his eyes to be aware of it, his monologue to Ichigo directly proves that.
No, the line was Ulquiorra saying that he never showed Aizen the form, which can be true without making it impossible that Aizen is aware of it. Ulquiorra's form not being factored into the rankings is headcanon. Proof that you haven't read the manga
Yammy is an Espada and he is far stronger than Ulquiorra, thus your claim that Ulquiorra is the strongest is wrong.
No, the line was Ulquiorra saying that he never showed Aizen the form, which can be true without making it impossible that Aizen is aware of it. Ulquiorra's form not being factored into the rankings is headcanon. Proof that you haven't read the manga

Yammy is an Espada and he is far stronger than Ulquiorra, thus your claim that Ulquiorra is the strongest is wrong.
The reason for Ulquiorra’s statement was to recontextualize his power. He claimed that only he had attained such a transformation, noting that he was special from the rest. Uryuu reinforced this by saying Ulquiorra’s reiatsu was so overwhelming that it didn’t even resemble a reiatsu lol. Ulquiorra’s feats also blows Halibel’s out of the water so his 4th ranking was already wrong from the get-go and destroys your argument. If Aizen took into consideration his second release (which the story clearly implies that he didn’t) then he would have at least made Ulquiorra above Halibel.