Yes to S&P 500 fall and maybe not to weaker dollar.
USA is now the largest oil producer in the world. It wont be good for the economy as a whole as interest rates will be forced up by inflation based in a higher oil price. BUT, there are a couple of hundred U.S. frackers reported to be about to declare bankruptcy and they own billions of dollars in outstanding loans to various banks, mostly in USA. So that could be a very large saving grace for USA.