The sentence that should have commas removed from its restrictive clause is:
The dog, that is performing right now, is going to win.
The correct form should be: The dog that is performing right now is going to win.
In this case, "that is performing right now" is a restrictive clause providing essential information about the dog. It should not be set off by commas. The other sentences use non-restrictive clauses, which are correctly set off by commas.