Under current law, a corporation is treated as a person for some purposes but not for others. Under the OP's approach, if a human chose to incorporate, would that mean that the human no longer had the right to vote? After all, corporations can't vote.
As for student loans, the loan was made to the individual. The borrower couldn't transfer the obligation to a different person (even his or her own corporation) and thus escape liability. The borrower would have to get the lender's consent, which obviously would not be forthcoming. Future loans could be set up this way if all parties agreed, but, again, they wouldn't; the lender wouldn't lend if the debt could be discharged through such a simple loophole.
I don't understand what you mean by a "class action corporation".
People who are incensed about corporate personhood should explain how they would feel about an executive order from Governor Brownback (or, worst case, President Cruz) confiscating the property of a corporation that the Tea Partiers dislike. Under current law, such an action would clearly be illegal under the Due Process Clause. That provision, however, protects a "person" from an arbitrary taking. If corporations weren't persons then they wouldn't covered. Corporate property also wouldn't be protected from unreasonable searches and seizures.
The outrage about corporate personhood is a major red herring. The better approach is to focus on specific issues, such as the Constitutional amendment to allow regulation of campaign finance. That would also address the problem of spending by individuals. Yes, Citizens United is a problem, but so is McCutcheon.