Would a Trump presidency end in disaster for the U.S.A.?

Probably less chance than if Hillary were president.

 Trump will try to build the economy. Those people who hate capitalism will all feel it is a disaster for America.

Impossible to say, since Trump has been big on noise and small on detail so far.  If that continues through the presidential race itself then it's not a good sign.  

Sooner or later a politician has to deal with the difficult area of policies.  Not just one or two ideas or vague pronouncements, but actual, comprehensive, worked out and well described policies.  They have to be feasible, workable, affordable and believable.  I have some doubts as to whether he can produce these.

Just for four years, and however much damage he can cause within that period of time to mess things up a little later down the road. I don't know. We've had sh*tty presidents and good ones. It'll all even out eventually, when Earth is consumed by the sun. I surely hope I don't have to experience war firsthand, but you never know. Things could go wrong even with a suitable pres.

I'm voting for Hillary.

Of course

No it will end with America being great again.