What does "ve'Chol asher Lahem" incorporate?
Yerushalmi Sanhedrin, 10a #1 (citing R. B'rachyah in the name of R. Chelbo: It incorporates even their names, which disappeared from all their storehouses and documents and rolled down the hole.
Yerushalmi Sanhedrin, 10a #2 (citing R. Eliezer: It incorporates even a needle that someone had borrowed from them rolled down the hole. 1
See Torah Temimah, note 28.
What are the implications of "Vat'chas aleihem ha'Aretz"?
Ramban and Seforno: Refer to 16:30:1:5 and note 4.
What does the Torah mean when it writes "va'Yovdu mi'Toch ha'Kahal"?
Ramban #1: They disappeared before the eyes of the congregation; one moment they were standing there, the next moment they were gone, leaving no sign of where they had just been standing.
Ramban #2 (citing Ibn Ezra): They perished together with their children, who should have replaced them.
Sanhedrin, 108a: It means that they lost even their portion in the world to come. 1
Yerushalmi Sanhedrin, 10:4: Via a Gezeirah Shavah "Vayovdu" "Hayisi ke'Seh Oveid, Bakeish Avdecha!" - Tehilim, 119:176, the Torah is comparing them to a lost article that is sought 2 - so too, will the congregation of Korach be sought - and will merit a portion in the world to come. 3
This is the opinion of R. Akiva. See Torah Temimah, who, citing a Pasuk in Shmuel 1, 2:6 poves that Korach will arise at Techi'as ha'Meisim. See also note 29 - that this is the majority opinion. Seer also answer #4.
See Torah Temimah, note 30.