With Trump, a VERY DIFFERENT presidency. Exciting!

By the end of this week, what could well be one of the most unorthodox, idiosyncratic presidencies in American history will be underway. The gap between Donald Trump and Barack Obama – in temperament, worldview and techniques – could scarcely be wider. At best, the new administration could deliver a much-needed blast of fresh air – but it could also prove profoundly, perhaps dangerously destabilizing.

The last two months, however, have provided a range of clues as to what we can expect.

Trump's Jan. 11 press conference – together with the handful of interviews he has given since his victory – offer perhaps the best idea of his priorities. By and large, however, the incoming president has communicated with the outside world through social media.

At worst, his utterances have reinforced almost every negative perception Trump's detractors have of him.

For a man who is now the most powerful in the world, the incoming president seems dangerously thin-skinned, almost bizarrely focused on his own celebrity and relative position to other figures in popular culture. In early January, he devoted two tweets to the relative performance of Arnold Schwarzenegger's new series of "The Apprentice" to his own.

Still, Trump's Twitter habit can yield dramatic effect. That's been particularly true when it comes to taking on major corporations, particularly manufacturers he accuses of taking jobs abroad.

Ford, General Motors and Toyota have all been on the receiving end of Trump attacks over proposals to shift jobs to Mexico and elsewhere – some of which have already now been publicly reversed. At the Detroit Motor Show earlier this month, an industry leader told the Guardian that every firm now feared being on the receiving end of the new president's social media feed.

On defense, Trump blasted Boeing and Lockheed Martin for cost overruns on a new Air Force One and the notoriously troubled and overbudget F-35 Joint Strike Fighter. On both, he will likely now get a better deal.

Whether that will work as effectively in the political and international arena is, of course, less certain. Trump's attempt to use a similarly blunt approach to signal a tougher stance toward China has already antagonized Beijing, particularly when it comes to Taiwan. On North Korea, Trump appeared to set down a red line in saying that a North Korean nuclear missile "wouldn't happen". It's far from clear what that will mean – and, as we saw with the Obama administration on Syria, setting down ill-defined messaging can dramatically backfire.

On Russia, Trump would really like to come up with some kind of global "grand bargain", perhaps tying together a nuclear arms deal that could save both countries money. Whether he will truly be able to strike a deal with Vladimir Putin given the political pressures at home, however, is rather less clear.

With Europe more broadly, the fact that multiple countries have increased their defense spending does allow Trump to claim at least a modest victory, even if in truth such developments would have happened anyway. His personal enthusiasm for "Brexit" – he has made a point of meeting with several hard-core "Brexiteers" since his election – may also do the UK a much-needed favor. Relations with German Chancellor Angela Merkel, however, look less likely to be smooth.

After the inauguration, Trump will be thrown in the deep end of the actual workings of government. Building the systems and structures for that may well have been his real focus during the two months he has been sequestered in Trump Tower. Here too, however, he looks set to take America down a route very different from anything practiced by his predecessors.

For Trump, it is now increasingly clear, his own family networks will be central to the presidency in a way not really seen since the Kennedys, perhaps not even then. Trump's son-in-law Jared Kushner will be perhaps the key figure. It's hard not to imagine that the family must be at least toying with the idea of using daughter Ivanka to establish a true political dynasty.

Trump will also be surrounded by a wider group of often equally unorthodox ideologues who he has given voice to in a way they may well have never thought possible. Figures like Steve Bannon, former head of right-wing news website Breitbart, now have an unprecedented opportunity to influence both strategy and access to the president. As long as Trump keeps delivering for them, their loyalty is also likely guaranteed – which is more than can be said for those Republicans in Congress and beyond who never wanted him to get the nomination at all.

According to some estimates, Trump's Cabinet appointees are so affluent that their combined net wealth is equal to that of a third of the rest of the U.S. population put together. Figures like Secretary of State Rex Tillerson – a former Exxon Mobil CEO – are now charged with using their business acumen to win deals for the country at large. If they do not succeed, the former "Apprentice" star has made it clear that some of them will get fired.

That's perhaps less true of incoming Defense Secretary James "Mad Dog" Matthis. In his confirmation hearing, the highly respected former Marine disagreed with Trump's statements on a variety of issues, not least Russia. His presence dramatically increases the administration's legitimacy on national security Should he ever quit, the damage would be considerable.

The appointees' jobs will not be easy – not least because the president may not be giving them that much guidance. One of the more unexpected moments in Tillerson's confirmation hearing came when he admitted he had yet to have a detailed discussion with Trump on where they stood on Russia.

Even with celebrity boycotts, the inauguration will be, as Trump himself predicted, a "great show". To many in America and the wider world, it may feel like something from the decline and fall of the Roman Empire. But it will also be something else – the largest and most geopolitically important reality TV experience of all time.

It may or may not Make America Great Again. But it looks set to be compulsive viewing.