To suggest that the president of the United States has no need to follow ethics laws, and that they should be changed to suit him is ludicrous! One of the top jobs of a country leader is to protect the well being of it's citizens. If he can't be expected to follow basic ethics guidelines, then we may as well chuck him in the same pile as Starlin and Pot before he even starts.
No, Congress should not change ethics laws for Trump or for any future president. The purpose of the ethics laws is to ensure that presidents are chiefly accountable to the American people, rather than beholden to foreign governments. Mr. Trump should be held to the same ethical standard as presidents before him, to ensure that he does not have any personal or business entanglements that would result in policies that are beneficial to him, his businesses or foreign partners but are detrimental to the United States.
There is no need to change ethics laws because the ethics laws should apply to everyone. Trump can be expected to follow ethics laws, regardless of what Gingrich has to say. The Republicans are just flinging mud at Trump, just like the liberals are. Trump knows the ethics requirements and he will follow them.
Congress does not have the power to make laws curtailing presidential power. The President's powers are laid out in the Constitution and Congress has no power to strip or curb them. If the President exceeds the will of the people than the President should be voted out at the next election. If the President commits impeachment worthy infractions, Congress should impeach him or her.