ok, now that it's working for me, Here's some ideas as to what else could be added:
1) ability to 'slide' around the visible target area, possibly using the arrow keys (up key=N, down key=S, etc). It's easy to get "lost" with out a fixed reference point (in my mission building missions, the player aircraft ALWAYS flies north, so there's that reference). In my screenie above, the river runs N/S (see #2 below)
Using the zoom is a bit difficult to get the vertical view necessary (for the most part) in placing target items, hence the need for the ability to 'slide' around.
2) possibly adding an orientation compass rose. Knowing that on ALL maps, "up screen" is always North, allows one to be able to see the direction or facing of the placed object (n, e, s, w). One can then estimate/guestimate the facing of the object.
Even knowing this a Very early beta, there is stupendous possibility here!
personally, I think the best thing about it right now, is that it reads the tile TODs, which allows you to 'see' the open spaces wherein to place target objects. That is one of the most critical things to know in targetization.