hey I can help you out with the ponyville town some, for one you can see the train tracks in the overhead intro shot of ponyville directly behind the town hall tower (the line that goes through the field)
[link] <--- from the shot Im speaking of
you can see a good chunk of sweet apple acres in the left corner of that shot and is opposite to the entirety of the everfree forrest where you can see fluttershy's cottage (has a fense and chicken coop with a green grassy roof) and Pinkie's farm (only building that Ive seen with a cross shaped chimney) as well
so the river is a barrier between the forrest and the farm... also if you are putting the Carousel Boutique with the tented area of Ponyville then the river appears to run between that part of town and the town hall
good luck and awesome map!