I live in Pacific Palisades, the end of Tin Hau Temple Road...a little further than you.
1) My kids' pediatrician is in Causeway Bay. Going to Causeway Bay is quite close. For emergency, I prefer to go to HK Sanatorium. It is usually faster than St. Paul, and, (touch wood), if there are any problems, HK Sanatorium's Children Ward is much better than St. Paul.
2) For food, I usually go to the North Point wet market near Wharf Garden. There are more stuff there to buy.
My daughter is also 3.5 year old, and will start K2 in September.