Comps: Mishnah for the Future?

Source: Ben Zion Wacholder, Messianism and Mishnah: Time and Place in the Early Halakhah (Hebrew Union College, 1978).

Wacholder's thesis seems to be that many of the Mishnah's laws were intended for the Messianic period, when the temple will be rebuilt. I have some questions about this:

1. According to Wacholder, there were rabbis who believed the Jubilee would apply to the Messianic period, not their own time. If that is the case, why did Hillel invent the prosbul to circumvent the cancellation of debts every seventh year? He seemed to believe that those kinds of land laws were still applicable and thus needed to be reckoned with.

2. According to Wacholder, "The most-holy sacrifices could be consumed only inside the curtains of the sanctuary, and these existed only in the Tabernacle and the First Temple and will exist again in the Messianic Temple" (32). If that is the case, why do the synoptic Gospels refer to the curtain of the temple being torn from top to bottom (Matthew 27:51; Mark 15:38; Luke 23:45)?

3. Wacholder says that, in the eyes of the Mishnah's authors, capital punishment will exist in the Messianic period. This raises profound questions. Isaiah 11 says that the Davidic king of restored Israel will slay the wicked with the breath of his mouth. Yet, it also affirms that people will not hurt or destroy one another, since the earth will be full of the knowledge of the LORD.

Jeremiah 31 says God will write his laws on the hearts of the Israelites and Jews, meaning they won't have to teach people to know God. At the same time, it also states that people in that time will be punished for their own sins, not the sins of their parents.

But why are people being punished period, if God's law is on their hearts, meaning that they don't sin? Are the prophets referring to the judgment that will precede or introduce the Messianic era?