2) Given that corporations exist only as a legal construct, I'm pretty certain that the government has a great deal of lattitude in what it can compel corporations to do or refrain from doing. It's worth noting that the US law also treats corporations as people; however, it does so because of the law itself (1 U.S.C. §1); modifications to that law can alter the nature of corporations in US law.

Are there any companies with >$1bn annual revenue that do not do business outside the state that chartered them? If not, then it would seem this could fall under the 'power to regulate foreign/interstate commerce', no?

Whether or not this would be ultimately beneficial, or the principle that the constitution is trying to protect here (don't interfere in the affairs of lawful citizens) is more important in the end are value judgements, and difficult ones at that. I don't doubt that if my circumstances were different I would be making an argument like yours.

We already have a process for dealing with this: amend the Constitution. But unless and until it gets amended, it is the supreme law of the land, and we can't just ignore it because we think something it currently proscribes would "benefit the state".

(I also have a problem with "benefit the state" as opposed to "benefit we the people". The state itself is established for the benefit of we the people; it is not a separate entity with separate interests apart from ours.)

You must be joking. Supreme Court jurisprudence already says that Congress can regulate crops grown for an individual farmer's personal use as part of its power under the Commerce Clause (Wickard v. Filburn, 1942). Imposing corporate governance practices seems like small potatoes in comparison.