I think people are overreacting. When Obama was elected everyone was waiting for fundamental changes. In my opinion after few months people will understand that new president is not so different from the old one aside from appearance and speeches. Because you just can’t suddenly change the way world politics and economics works.
Except that you're missing the
reason those fundamental changes didn't happen(and, actually, in Obamacare they
did happen). Namely, Obama's party didn't possess complete control of congress (at points they did control either the house or senate but, so far as I remember, not both at once). Internal policy changes are funneled through congress for the most part, not the executive branch. Mind you, I'm not really an adherent the doom and gloom group, I don't think the world is going to go to hell because he was elected. As a final note, however, "world"
economics is already changing and he hasn't taken office yet. The Asian markets dropped sharply when it was clear he won.
Though, to be fair, it wasn't as sharp a drop as Brexit caused(in my understanding, I haven't had the time to do proper research yet). Real effects will have to wait until he's actually in office to determine, but many of his economic plans are the reason that foreign governments(baring Russia) didn't want him anywhere near the whitehouse. As the U.S. economy no longer really exists as an independent entity, it's tied too deeply into the world markets, as the world goes so goes the United States.
Still, all told, you are probably correct in that people are overreacting. Mr. Trump is primarily a showman, and it's very probable that half his rhetoric did not reflect his actual plans going forward. While I am dismayed about his victory, it is primarily on the grounds of personal distaste for his tactics and public behavior. I don't particularly like the idea that we American's can be lead by promises of violence and appeals to the lowest common denominators of fear, hate, and anger. As to his actual capability to run a world superpower successfully...I will reserve judgement for February.