The president will need permission to declare war.
Trump can in theory command the nukes to be fired without declaring war but this only works if there isn't any political opposition agains his case (i.e. it would be considered unpatriotic to disagree with his decision)
Given the general dislike for Trump there will be plenty of dissent if he decided to just send nuclear bombs left and right. The military would overthrow him pretty quickly.
So yes there are checks and balances and in the case of Trump they would make sure that he followed protocol.
You dislike him so your analysis of why he would be thin skinned has little value here too.
I have no personal interest in this as I can't vote, however I am not afraid of him more than Hillary (who is a known Hawk)
Trump's thin skin is a proven fact. He still isn't over the jokes over his small hands. He felt the need to defend his penis size in a presidential campaign. He attacks voters at his own events. He verbally insulted almost all minority groups. His default reaction to any criticism is to personally insult the critic.
I also don't see why anyone would want a thin-skinned man child in charge of the only superpower in the world. Being in the center of at least one pretty strong fraud case doesn't help either. The argument "he just says stupid things all the time, but he will be presidential and wise when he is president" doesn't even begin to make sense to me.