The problem with the turrets is that they're parented wrong so the turret geometry isn't using the local space of the root nodes.
In Blender you're going to have to use the python console to fix it (pick one of your UI panes and click the pane type selector and select 'Python Console'), then
- Pick one of your turret geos and clear parent on it (alt+P), then rotate it back to a neutral rotation (so the inverse of whatever the rotations on the Position node are) and apply that rotation
- Make sure the turret geo is still selected then shift select the position node.
- Go to the python console and enter "C.selected_objects.parent = C.object"
- Select only the turret geo and alt+g to clear its position.
- Rotate it -90 on it's local x axis (r x x -90 enter)
- Apply rotation.