JAG88
There would still be a blockade, albeit possibly not as vigerous. I can't see Byran selling war with the entente powers so that US industry can sell military goods to Germany. Especially given the attitude to Germany after its attack on Belgium.
Britain was ready to back down at the first firm gesture by the US, but it never came. There would be a blockade, but Britain would not be able to monitor or stop neutral traffic bound for countries other than the CPs, so trade would be diverted there and the neutrals would make a killing reselling goods to the CPs.
The war could have gone either way. Too many butterflies to tell for sure. It does boost the position of the central powers but how do the allies respond as there are plenty of changes that can counter much of the down-side for the allies. It could end up as a peace of exhaustion, or a Germany 'victory' with an exhausted state tied up trying to occupy vast areas of Europe and possibly with an unending guerilla war in Russia and a cold war with Britain. Or the allies play their hand a bit better and still manage a limited win as OTL.
Not too many, or at least none favourable o the entente. Money is a concern, France was done in 1914, most of its industry, coal and iron where in German hands now and was supported only by massive loans from Britain and loans taken by Britain in the US. Bryan was very outspoken against loaning to the combatants so no or little loans here, all purchases are to be paid in cash.
Once Russia is done the game is up for the allies, Germany is in a better resource and supply position (no Hindenburg program) and is in no hurry due to no US in the war. Use the less trustworthy AH troops to garrison former Russia and then knock Italy out of the war with follow on GE/AH attacks after Caporetto, cut them a deal and now is pretty much time to deal with the last 2 allies. Support and complement Turkish troops in the ME and take Egypt adding a few thousand Km to the British trade lines and then Libya, just to scorn the Italians, then cutoff British oil in Iraq-Persia.
I really dont think it would even come to fighting it in the West, but even if it comes to that Germany would have a lot more supplies, aircraft, guns and tanks than IOTL and the allies less with no US to back them up.
Germany is still likely to try USW with the resultant impacts on allied supplies [until convoying is introduced] and neutral public opinion.
Steve
No, USW was a direct response to the illegal blockade, no real blockade no USW, there is no need for it and you risk neutral opinion upon which your blockade running trade now relies.