In YOUR ideal world would America stand alone on its own without allegiances or alliances or responsibilities/obligations to other countries? Could America go it alone and survive or would it perish?

Only a few countries could ever go 100% isolationist and get away with it.. Because in the modern world you need all the resource types of mental and fuels and minerals.. and not many countries have reserves of everything..  The USA has reserves of most resources  but not all.. It would have to do a few bilateral trade agreements with a few nations to source those minerals..