>No chance that would hold up in court. Clickwraps have been tested in courts and are fully enforceable.

there may be no chance it would hold up in court, but not for the reason you say. it would have be be because "any words on on a modified document "signature" line would be taken as a signature" or "subverting a clickwrap license is theft of services" or whatever.

that "agreed" clickwrap licenses have been found enforceable is a separate fact about a separate issue.