Why do we mention R' Yehudah assigning the simaning of DeTza"Ch AD"Sh and B"AChV to the staff of Moshe? My wife suggested that since we read earlier in the haggadah that "kol hamarbeh harei zeh meshubach" one might get the impression that going on and on is the ideal. If one takes this approach, at some point one will inevitably find that one is talking to oneself, not one's student or child and the whole raison d'etra of haggadah and sipur is lost. Therefore, the author of the haggadah brings in R' Yehudah to remind us of the principle that a person should always teach "b'derech ketzarah," as that is the easiest way for a student to absorb information and retain it. Sometimes saying more does not enhance the message. I thought that was a nice chiddush.
Chasam Sofer writes (based on a Midrash) that the three items we focus on during the seder, i.e. pesach, matzah, and maror, correspond to different classes of people, much like the four minim we take on Sukkos. There are korban pesach Jews who are dedicated to sacrifice for the sake of religion; there are matzah Jews who do what they have to but it is without flavor or energy; there are maror Jews who are bitter about the whole thing. Hillel is the one who teaches us in Pirkei Avos, that we will start reading right after Pesach, that you should be like Aharon and be a "rodef shalom" and make peace among all people. Therefore, it is Hillel who is able to be "koreich" all these different factions together into one united whole.
"L'oseh niflaos gedolos levado ki l'olam chasdo." Of course G-d does miracles himself, without help. That's not we need this pasuk to teach us. It's more than that: as we know from the story of Balak and Bilam, G-d saves us from dangers that we don't even know are out there -- He "levado" knows what great miracles he has done and we are unware. And yet even more than that: G-d sometimes does something amazing now where the benefit only pays dividends years and even generations later. "Ki l'olam chasdo," only G-d who is eternal and can connect the dots through history, has full "awareness" so to speak, of how great his miracles are.
I posted two explanations before Y"T of the pasuk “Va’yei’anchu Bnei Yisrael min ha’avodah va’yizaku va’ta’al shava’asam el haElokim min ha’avodah.” The Radomsker suggested that the phrase "vata'al shavasam el haElokim" stands in contrast to the crying "min ha'avodah." Tefilah demands that we set our sights on great things. R' Ya'kov Moshe Charlap, however, suggested that **even though** the cries of the Jewish people were cries of pain and anguish about their being enslaved, nonetheless, G-d accepted those cries as if they were crying about the pain of the Shechinah. G-d understands that the right thought can sometimes be "nislabesh" is a less-than-perfect container.
The Sefas Emes quotes from the Ch HaR"IM that "Vayir'u me'od vayitzaku Bnei Yisrael el Hashem" means that when the people felt fear of the Egyptians, they cried to G-d in tefilah because they realized this fear was a defect in their emunah. By that same token, one can read, writes the Sefas Emes, the pesukim of "Vayi'r'u ha'am es Hashem va'ya'aminu baHashem ub'Moshe avdo Az yashir..." as meaning that because the Jewish people felt yiras shamayim, because their hearts were filled with emunah, therefore they sang shirah. Yiras shamayim can lead to great simcha and even shirah.