Forum Moderators: buckworks
I'm not a lawyer, but I've paid a few to create online TOSs for different types of sites. Online Terms of Service agreements aren't like traditional contracts and there's a lot that's still left to interpretation.
Regardless of what your Terms say, you're still left with the burden of any dispute. The more rights that you attempt to limit with your Terms, and the more specific those limitations are - the more burden you'll have.
I'm not sure what the statute are surrounding a cooling-off period, but I doubt an online TOS would hold up if someone had a good enough lawyer.