If you have Resistance...
Use the option on the side menu to display object IDs, zoom in on the object you want removed and note its ID number. I am not sure if you can delete it, but you can move all the objects into the middle of the ocean. Then in the init.sqs use the following line...
(object 1234567) setPos [0,0,0]
Except replace 1234567 with the ID number and 0,0,0 with the coordinates of a good out-of-the-way location. This works on any map object from houses to lamp posts to sections of forest.
If you do not have Resistance you would probably have to use the nearestObject or whatever command to reference the the map object you want removed.
WARNING:
If you change the position of map objects they will remain changed for the player until he reloads the map!! Basically, if your mission calls for all the buildings in Lipany to be moved to the ocean and the player plays your mission and then plays another one that is based in Lipany, none of the buildings will be there and that mission will get messed up.