If corporations are people, equivalent to flesh and blood people, then they must "live" by the same laws and regulations. For instance, until someone is of legal age, they cannot sign legal contracts...but corporations can from day 1.
If corporations are equivalent to people, then anyone who owns a share of stock is a slave owner.
If corporation are people, then they must have the same legal political contributions to candidates limits as individuals, and not a penny more.
If corporations are equivalent to people, then why can they hide money legally overseas to avoid taxes...and have a different tax system.
If corporations are people, what gender are they? Are they all male? If so, then they need to file with selective service. If they are all male or all female, then they can't merge (marry) in most states. If they are randomly male or female (like we are), then 2 male corporations can't merge. Corporations also shouldn't be able to merge with multiple other corporations because that could be considered polygamy.
No, corporations aren't people, but they are another type of legal entity...separate than people. A corporation can live forever. A corporation doesn't have a soul. If they are considered people, and they don't have to follow the same rules, and have the same rights and responsibilities, then they are a different class of person...possibly a higher class than flesh and blood people.