First, all art schools of the calibre he was applying for need a sample of your art work as part of the application. I have seen it online and it's rubbish. He was a bad artist.
Second, there would still have been a war as yanks like Henry Ford would have found someone else to fund: war makes money.
Note that, at the founding of the League of Nations, the yanks blocked a Japanese attempt to insert a racial equality clause, so that set the tone for the coming war.
Also, the condition for Washington entering the war in Europe was that the British Commonwealth hand over all our gold and allow yanks access to our markets, something I would happily take away.