There is no big difference between round 1 and round 2. The chance for round 3/4 depends. For example, if you include MIT in your top 5 list, it only has two rounds, no matter you are domestic or international applicant. With all the e-application, I don't think where you submit your application matters. Ofcoz, you have certain advantage, e.g, easy to visit schools, while you are in the States.