It sounds like a very important role of your coursework will be to get a more refined idea of what research you'd like to perform. I'd recommend taking classes in each of your areas of interest. The more advanced classes might give you a better idea of research in that area. These are probably the classes the PhD students will be taking.
I think a goal of 2-3 publications in one year is pretty lofty, but it depends how motivated you are and how much work you have to put into each of those publications. I think one solid publication (long paper, good conference/journal) will already give you a substantial edge in PhD admissions. This is a good goal; if you can do more, all the better! But I would hate for you to feel like you didn't meet your goal, and not be satisfied with one publication. Honestly, even if you go through the trouble of submitting a paper and it gets rejected, that is still an incredibly valuable learning experience.
Feel free to email / google hangouts me at adam.r.drescher (at) gmail (dot) com if you have more detailed questions, want my perspective during your graduate school experience, etc. I'm happy to help.