I haven't done physics in VCE but from what my friends have said it sounds like you need more logic to do chem questions than physics. Anyway, that's not the point of this thread...
OP, what career/course are you thinking about entering? That should have a big impact on your decision. If you are going to do commerce, science, engineering etc, spesh is almost a must have (unless you're thinking about the bio side of science). If you are planning on doing a health science, then I believe chemistry is very important if not necessary. Business management is not needed for anything, but since you are doing that in year 11, it may be best to keep it. Physics will only be handy if you are going to major in physics, or are doing engineering, but even then you catch up very quickly in uni, much more so than if you had not done spesh or chemistry. Of course, italian isn't needed for anything but if you were to major in italian then you would be able to progress further.