"The Torah speaks about four sons" - Rav Wolbe comments that if the Torah felt it imperative to write four separate pesukim to parallel the four different sons, it implies that every child must be spoken to in a language that he can understand. Even the wicked son must be answered with a response that is hand tailored to his personality.
"Regarding the son who doesn't know how to ask, you begin to speak to him" - Rashi explains that for such a child one should tell aggadic explanations that draw his heart. Rav Wolbe explains that the Seder Night is aimed at opening the hearts of our children. The Korban Pesach is referred to as "avodah", for through its performance Bnei Yisroel began their avodas Hashem. True avodas Hashem can only be achieved when one internalizes in his heart that there is a Creator Who took us out of Egypt, and we are His servants.
"Because of this (the Pesach, Matzah and Maror) Hashem acted on my behalf when I went out from Egypt" - Rashi explains that we were redeemed in order to perform His mitzvos. Rav Yeruchom Levovitz would say that people think that because they want to eat they must therefore make a bracha. However, the opposite is true. The reason we were created with the need to eat is so that we should have the opportunity to say a bracha. Likewise, we do not perform these mitzvos because Hashem took us out of Mitzrayim, rather, the purpose of Yetzias Mitzrayim was to give us the opportunity to perform these mitzvos.
"A person is obligated to perceive himself as if he went out of Egypt" - Rav Wolbe points out that the Haggada revolves around each individual person. Thus we say, "Each person is obligated to perceive himself as if he left Egypt"; "Hashem acted on my behalf when I went out fromEgypt," and so on. Rav Wolbe goes on to explain. The Seder Night is set up in question-answer form because a question stems from one being aroused to ask. The Gemara explains that when King David is described in the pasuk as one who "knows how to make music," it means that he knew how to ask questions properly. The correlation between making music and asking questions is that they both are borne out of hissorirus - being aroused. The questions in the Haggada were designed to arouse us to delve more deeply into the events of yetzias Mitzrayim and their implication to our avodas Hashem. Only once one is aroused, can he feel as if he himself left Egypt.