You are correct that He must necessary have knowledge of the person before He can choose that person. However, you are making two critical errors here:
1. When saying that He "chooses according to His good pleasure" it is meant that He chose as it so pleased Him to choose. That is, He was pleased to make the choice He made. It does NOT necessarily mean that He chose based on some pleasurable attribute of the person. It simply means that it pleased Him to choose as He did.
2. He is not pleased by the object of His choice (that is, in the transitive sense) but rather pleased by the choice itself.
Therefore, it was something in the persons that He knew that either pleased Him or displeased Him.
See above.
I don't think you will find a Weslyan who would disagree with that statement. Indeed no God respecting Weslyan would dare to state that there was any "attribute" within a person that inclined God to choose that person. It is not even the person himself, but what God foresaw IN that person. That being the person of Jesus Christ.
The dilemma that the Calvinist has is that if God chooses without regard to anything in that person and it is not because of foreseen faith, then God is either choosing arbitrarily, or he actually is a respecter of persons.
The Arminian/Weslyan believes that God is a respecter of the One who dwells within his elect and not of the elect themselves.
Isn't it an odd coincidence that He just happened (1) to foreknow each one, and (2) to have been pleased (according to his good pleasure) by only those who were to be believers?
And isn't it a coincidence that the bible says, "those He foreknew He predestined..." and "elect according to the foreknowledge of God..?"
It just works for me, Fru.