I'm no expert on US politics, do the executive orders have to be ratified by Senate or Congress, and will the Republicans gaining control in the mid-terms put an halt to the man?
Executive orders, in theory, are law as soon as they're signed. In theory, they're based on the President's pre-existing powers as head of the Executive Branch. Congress, which is made up of the Senate and the House of Representatives, can
overturn them, as could the Supreme Court, as part of the system of checks and balances written into the US Constitution, but Congress is controlled by Republicans already and, while SCOTUS is not, that's because the Republican-led Congress spent over a year refusing to even hold hearings for Obama's nominee to replace Scalia. So we're sitting at an eight-member SCOTUS that will be nine as soon as someone Trump nominates is confirmed.
Of course, he's promised that his nominee will overturn
Roe v. Wade and probably
Obergefell v. Hodges. So that's not going to help.