If Roosevelt wanted a war, at all, he would have joined the war long before Pearl Harbour. There was ample reason and opportunity to declare war. What you have essentially described is somebody taking a political stand, without wanting to join the war. You have essentially listed his diplomatic actions making his ethical stance clear, short of war.
This can be seen also (IIRC, and feel free to correct me) in the American navy's actions in the specific. To the Japanese it might well have looked like a stranglehold being placed on supply routes, but to the Americans it was no doubt a sensible bolstering of defences in territories next to a literal war zone. At best this is political action, short of joining the conflict.
Given that his nation was still recovering from the cost in life of the first war, it is understandable that he would want to do something, but would be unwilling to commit to such a sacrifice unless forced to. (Which is the context that Chamberlain's appeasements before the law should be remembered).
Once Pearl Harbour happened, the US had no choice but to declare war not only on Japan, but on Japan's allies.
Of course, it should also be noted that whom Hitler wanted a war with, is not as direct a path to trace as many assume.
First we have to consider that Hitler expected the UK, and much of Europe to either join his side, or step aside, as he wiped the Bolshevik Soviet threat from the face of the Earth. His war was a crusade against Sovietism, and the races he held responsible for the ideology he hated.
Before the war, during the depression, politics had polarised around the world, and there was a constant fear of communist revolutions across the world. Fascism rose as a response, and Hitler saw himself as the respectable face of extremism, and the one that right ring, conservatives, would side with to protect themselves from the threat of communism.
Second we have to consider Hitler's own ideology. There was much in America he saw as harmful influences: Racial populations, smoking, drinking, jazz music, and certain political stances, a strong Jewish population, and so forth (heck, we know this was at least perceived as a problem in America because of some of the less than charming factions being vocal at the time, and remaining vocal throughout the civil rights movements).
