underused after 1900 pods

  It would all depend on the circumstances.  Yes if the USN attacked the blockading fleet they have a massive numerical advantage but it would assumable mean war with all three nations.  [Wasn't aware of the Italian naval involvement in the affair.]  As such they should expect retaliation and in this case that would depend heavily on how closely Britain and Germany collaborated as a result and the reactions of other players.

  Basically Britain has the fleet to crush the US navy if it comes to a major battle between the USN and a powerful RN fleet sent to the region and Britain has a number of bases in the region, including Trinidad [as mentioned] but also Jamaica and a bit further north Bermuda as well as other colonies.  Also with the large force of cruisers at this point there is a good opportunity for a powerful blockade of US ports.  Also if Germany and Britain are able to work together then you have a British army with recent experience from the Boer War and at least some elements of the very powerful German army.  The US may in the wider term be too large to be conquered but it starts with a very small army and you could see a lot of damage done to it, especially its coastal regions if its opponents peruse the war aggressively.  Which is a possibility if the attack on the blockading forces is seen as a sneak attack or if the US attacks Canada.  [Canada is likely to declare its neutrality in such a conflict but whether the US accepts that would be an issue].  Without those cases Britain might be a lot more willing to seek a peace settlement although its likely to be angry at any attack on its ships.

  In terms of other powers getting involved then the big questions would be the dual alliance of France and Russia and the rising power of Japan:

a)  In the former case it might seek to attack Germany while that power is distracted but this would be a hell of a risk as Germany is easily the strongest power in the world at the time and also this would establish a British-German-Austrian-Italian alliance.  Even with the US as a possible ally this is very likely fatal for the two powers as not only would there be much capacity - even if the will was there - for US support in the near term and everybody was expecting a short war but also since such a move would immediately threaten the homelands of Britain and Germany it would make France especially the priority target for the alliance.  As such while such a move would be good for the US it would be a bloody disaster for the French and probably not good for Russia.  The two might move against Germany if the US was seen as being successful some time into a longer war and had drawn away a sizeable proportion of British and German strength but I can't really see then joining the conflict in the early stages.  Also if the US action was seen as unjustified their likely to be influenced by that.

b)  Japan, while it doesn't have the best relations with Germany, which organised the ad-hoc alliance with France and Russia to limit Japan's gains from its victory over China in 1895 is allied with Britain and while not formally committed under that alliance to join the war - unless another nation joins the war against Britain - it may find it convenient to.  There is tension with the US over racial discrimination against Japanese migrants both to the US itself and the recently established US control over Hawaii, which also has a significant Japanese minority.  Furthermore the US has recently put down, with a fair degree of brutality, the move for independence in the Philippines - which IIRC occupied a good proportion of the US regular forces.  Japan hasn't yet achieved the level of prestige it OTL received by its victory over Russia but is seen by a fair number of people both in Japan itself and elsewhere in Asia as the leading Asian power and an opponent of control of Asia by external powers.  Also the Philippines both lie across important Japanese trade lines and are also vulnerable to Japanese attacks, with the US occupied by a major war with 3 European powers and the Japanese control of Taiwan means they have the potential to threaten US control of the islands from the south as well as the north.  Hence I could see a significant probability that Japan would seek to 'liberate' the islands and possibly even try and reach towards Hawaii - as I think we discussed in another thread a few months back if the US was heavily occupied by fighting with the other powers.

  Also there is the issue of nitrate supplies.  Those come largely from Chile and neighbouring areas and are important as the basis for both fertilizers and modern 'smokeless' explosives used in the more modern weapons.  Britain has strong economic and political influences in the region and also in an alliance that would control the seas its likely that the US would quickly find itself cut off from such supplies just as it would want to massive expand production of munitions.  They can revert to older gunpowder based weaponry but those are significantly less efficient and again would need to sort out production lines, for saltpeter especially.  Its possible that the US might somehow produce a Fritz Haber who develops such a process to manufacture nitrites from atmospheric nitrogen but doing that and converting an idea into a large scale industrial process in the middle of a major war that could see large areas of your industrial heartlands fought over would be a hell of a task.  Especially since at this point Germany is definitely the primary power when it comes to the chemical industry.

  Well it would depend on the circumstances but the Democrats have a lot more votes and representatives in the south.  However how much might it cost them elsewhere?  Likely that regions which are more liberal could be less supportive if the Democrats still have a significant Dixecrat support they depend on.  In this case the Republics might still be the more liberal party and the Democrats the more reactionary.

  Also unless the Civil Rights movement has got nowhere and Jim Crow is largely in place a Democratic Party depending largely on white conservative southerns are likely to have little support among the blacks and possibly some other racial groups. 

  As such the position is likely to be less favourable to the Democrats than them simply having a markedly stronger support in the south and all they have elsewhere nowadays.

  Basically yes.  I'm a social liberal and while I value a good economic base I don't assume minimal government is automatically a good thing. 

  Well a lots definitely going to be different in comparison to OTL.  Also is the religious right going to be a major influence on the Democrats here rather than the Republicans.  In what way and how that might differ I don't know.  Possibly with the history of connections with organised labour and involvement in government activities, which is generally opposed by the religious groups I understand the Democrats would be more deeply divided than the republicans were OTL?