Why would you use a C Corporation to solve this problem? You'd probably get very similar protection --- perhaps the same protection --- from an LLC.
Here is roughly the mental model I've built about incorporation choices (there are several lawyers on HN that may stomp on me for posting this):
* LLC - cheapest, all money goes straight to principals as if each was a sole proprietor or freelance, tricky to issue equity to employees
* S-Corp - enables the FICA "reasonable salary" cheat, enables employees to easily get shares, enables principals to get W2 wages instead of paying quarterly on everything (LLC's can get this too if they "file" as S).
* C-Corp - company pays corp taxes, company can have multiple classes of shares.
All of these structures provide people acting on behalf of the company, having disclosed that fact clearly to their counterparties, with a reasonable belief that they are authorized by the company, some measure of protection against contract claims.
It's also very important to remember, if you're incorporating to avoid a foreseeable legal event, that corporate liability protections don't shield you from torts. The DMCA stuff you're talking about is tort law. If you are negligent or deliberately cause damages or commit fraud, the corporation isn't going to protect you. Similarly, some things you'd assume would be a matter of contract law (such as payroll) might not be depending on what state you're in.
If I was in your situation, I wouldn't consider laying out money for a C-Corp, and I'd only do something beyond the barest formality of an LLC if I had more than a couple founders or more than one "kind" of founder.