Yes, J7 houses four of the schools on base: Armour, Artillery, Tactics and Infantry. The Engineers have their own building as pointed out in Vern's post.
G1 = Catholic Church and Chaplains' offices
G2 = Protestant Church
G3 = Firehall.
A 25 metre range used to be in the top half of the "survey area" betwen G3 and G2, alongside the road paralell with it. Most of the "Survey Area" is wooded.