A few things you can be sure of:
The author means free because there's a footer link or something else that he doesn't want removed. No one does that to code that they want modified.
If he went through the trouble of doing that, he probably made sure that it will take you longer to decrypt it than it would take to create your own template.
Is it really a big deal? I'd probably either live with it and accept the terms, or dump it completely.
Also, since you don't know everything it's doing, it might have "phoned home" with the domain it's being used on, so he can watch for unauthorized changes.
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