I'd also have a look at SBuilderX and Whisplacer in
addition to ADE.
With SBuilderX you can create some custom landclass
polys to add those small ponds in the area as well as
acurately shaped forestation. And any plateau effects
can be eliminated with sloped polygons in SBuilderX.
Whisplacer is great for adding hangars and other buildings.
Unfortunately I've got a pretty full schedule of travel
for the next few weeks, otherwise I'd be glad to help
as I've done the sort of things you need with several
FSX airports, using those three tools.
Here isa an example of what can be done. This is "my"
Tokol, LHTL, outside of Budapest. Note the landclass
additions...small lakes, forests and the buildings.
And here is an oblique view of the original FSX default Tokol:
And the same view of my enhanced Tokol:
I used a Google Earth image for reference when placing the various landclass
polys that define the ponds and forests. Also all the other elements that
are missing in the FSX default airport.
There appears to be a pretty good image of your airport in Google Earth and
looking at the 'street view' on the hiway to the south that large hangar
resembles one of the 'stock' FSX hangars so you should be able to add
that one and another similar one further north with Whisplacer.
Also, it looks like the GA sheds can be done with FSX stock buildings.
Paul