I would like to see back plating added to the lighthouse's that prevent the light from being cast on the land behind it.
This would not only be more realistic but would also prevent the annoyance of your NVG's constantly auto-correcting when near them and stop highlighting the horrible globally lit grass (see additional info for example).
Two examples from my part of the world.
http://www.issva2014.com/media/800x800/cape-schanck-lighthouse_7.jpg
http://printingaustralia.com.au/wp-content/uploads/2012/02/Cape-Otway-Lighthouse.jpg
Global illumination of the grass, even though it's on the back side of the hill and not directly lit by the lighthouse.
http://cloud-2.steampowered.com/ugc/594759049822912473/F587C6B82D45A63F0516B1716786D17DF6E2E439/
As for the search light aspect of them, I'd rather have searchlights added, and I'm sure they will be eventually. :)