Question 2: Why does the Vilna Gaon hold that you should pick up the lulav and esrog normally, the way the mitzvah is done and then say the blessing? You technically don’t even have to have in mind to not perform the mitzvah until after the blessing is said.
A. The Shulchan Aruch (Orach Chaim 651:1) says the mitzvah of lulav and esrog is to take them into your hands.
B. Normally we say the blessing before doing the mitzvah.
C. The language of the blessing on the mitzvah of lulav and esrog is blessing Hashem “on the lulav being taken,” not blessed is Hashem “for taking the lulav.”
Answer: The Rabbis specifically enacted the blessing to be past tense and not future tense so that it’s inclusive of already having the lulav and esrog already in one’s hands instead needing to pick it up immediately upon saying the blessing, since blessing are usually said with item in hand and then the action is done whereas here the action is done by putting it in his hand so the. Lessing is worded in a fashion where you could say the blessing in a matter which makes sense while still having the mitzvah in your hands (See footnote 42 on page 89 of Dirshum Mishna Berura.)