I walked a lot and fell asleep just after I posted. All bar 1 correctly identified:
1. Dorchester south. - paul7575
2. Above Bincombe Tunnel, Near Upwey. - MVR
S&T▸ Used to be a station (halt) there,
IIRC▸ ▸ . Upwey Wishing Well? - paul7575
Site of Wishing Well Halt, about 1.4km from the Wishing Well itself. - bradshaw
See
http://www.passenger.chat/258443. Broadway station (Abbotsbury branch) - bradshaw
with thanks to bradshaw and stuving for futher information
4. Custom House Quay, Weymouth Harbour, looking West. - RichT54
5. Dorchester West - bignosemac
6. NOT yet correctly identified!