Well... I enjoy playing with optics or as a spotter/scout. Meaning I use binocs tons and I use the map for marking what I see. IF I do not exit optics, open map, close map, raise weapon and then zoom, I lose sight of the area I was targeting.

It is also strange to have to raise my weapon before using optics. It would be better if you were unable to zoom in when the weapon is lowered than the way it is now.

edit:
Known issue: http://alpha.arma3.com/known-issues

My experience comes from civil aviation, 99.9% airplanes. Where, with all sizes of airplanes, birdhits are an issue. The damages can be quite severe both to fuselage and engine.

Agreed, it would be really unlucky. Yet, incidents occur frequently especially near airports and very often this results in the airplane returning to the airport to make sure no damage occurred.

FAA animation: http://youtu.be/imDFSnklB0k (granted a flock of birds, but resulting total engine failure on BOTH engines)

I suppose it would be rather easy to have a difficulty setting turn on/off bird collision depending on your gameplay. I don't see it would be that difficult for BI to implement =)

edit: Found this one about a helicopter, http://youtu.be/98wSezE7WJY. Again, not saying it should be very common, but every now and then it could be a possibility. Would also make interesting scenarios.