Why does the Torah need to inform us that a Ger too, must bring a Korban Pesach when we do?
Rashi: Because we might otherwise have thought that he brings it (not when we do, but) when he converts. 1
Ramban: Because we might otherwise have exempted him from bringing it, seeing as neither he nor his ancestors left Egypt. 2
Just like we did - when we came under the wings of the Shechinah. See Oznayim la'Torah.
Ramban: Even though in Sh'mos 12:48, the Torah includes Geirim in the Mitzvah, that is because those Geirim (the Eirev Rav) left Egypt together with Yisrael. See also Ramban Devarim 6:23.
Having already taught us that a Ger does not bring a Korban Pesach when he converts by Pesach Rishon in 12:48), why does the Torah need to repeat it by Pesach Sheini?
Oznayim la'Torah #1: Because we might otherwise have thought that he does not bring a Pesach when he converts since the Pesach Rishon is a communal Korban, which the Tzibur brings, whilst he is just a Yachid, but he does brqing a Pesach like Yechidim bring a Pesach Shein.
Oznayim la'Torah #2: Because the main objective of the current Pasuk is to teach us that a Ger who converts between Pesach Rishon and Pesach Sheini must bring the Pesach Sheini. 1
Like Rebbi in Pesachim 93a, whose opinion is Halachah. See Oznayim la'Torah.
To whom are the three categories "Lachem, ve'la'Ger u'le'Ezrach ha'Aretz" referring?
Seforno: "Lachem" refers to everyone, in the Midbar and "la'Ger u'le'Ezrach ha'Aretz" to converts and native Yisre'elim in Eretz Yisrael, 1 respectively.
A convert does not inherit land in Eretz Yisrael. One without land is exempt from Aliyah le'Regel. The Pasuk teaches that even so, he is obligated to bring Korban Pesach. (This was inspired by the Tzelach, Pesachim 3b ? PF.)
Why does the Torah insert the (otherwise superfluous) word "u'le'Ezrach ha'Aretz"?
Oznayim la'Torah (in Bo, 12:48): To teach us that, although a Ger does not own land in Eretz Yisrael, he is like an Ezrach who does.
