Would all the laws and executive orders he has signed still stand?
Not any of the Executive Orders. The laws would stand only if they would have become law in the absence of a Presidential signature.
Article I, section 7 says: "If any Bill shall not be returned by the President within ten Days (Sundays excepted) after it shall have been presented to him, the Same shall be a Law, in like Manner as if he had signed it, unless the Congress by their Adjournment prevent its Return, in which Case it shall not be a Law."