1) That's nice, but the devs are far, far from ever doing Pacific. They've just recently announced Ostfront, which means at the very least, some years before they even start thinking of Pacific.
2) That may come eventually. I believe there are a couple fanmaps of it, but no official maps. Its possible that the devs might make one eventually, but currently, they are on Battle of the Bulge, and Ostfront.
3) Ship v ship combat is quite difficult, and also goes against the ideas of FH2, which is giving mass combat. Currently, there are a couple ships in the mod, but none on any maps, and probably will continue to not be. There is simply no place for them right now.
4) Impossible to do effectively on the BF2 engine. The only way causes untold amounts of lag because it turns every window sill and position into a vehicle. You simply aren't going to see this on the BF2 engine.