You seem to have a slightly warped view of the power of the Presidency.
He would have to use his veto power to kill the budget in order to kill the TSA. The War of Drugs is a legislative issue, so all he could do there is refuse to enforce those laws while in office. It would also be within his power to pardon all non-violent drug offenders in federal prison (but not state prisons). He couldn't disband the TSA, but he could require them to weave baskets or something all day instead of enforcing the law.
Paul has been a constitutionalist first and a libertarian second. I don't believe he would break treaty obligations, although I'm sure he would work to lessen them while in office. He would certainly pull all of our troops home (except if bound by treaty, see above). He certainly wouldn't start a war of aggression, although I believe he would decisively defeat any state enemy that attacked us during his term.
There are a LOT of things a "rogue President" could do. I'm a gun nut, so the first thing that springs to mind is the FOPA '86, which banned new-manufactured machineguns, and the GOA '68, which allows the Attorney General to authorize an Amnesty, which could allow individuals to manufacture and register machineguns, suppressors, short-barrelled rifles and shotguns, etc. There's not reason that Amnesty couldn't last all 4 years.
Finally, let's not forget that for the past 40 or so years, the federal government has primarily exercised control via regulation, not law. Think of all of the controversial rulings that you've lived through, whether they be from the EPA, BATFE, FTC, etc. All of that could be repealed in a heartbeat, as ultimately, the President acts over those agencies in the same way a CEO acts over a corporation.