Pathfinding
 

I didn't see anything on this subject, so here we go: Has pathfinding been improved? Silent Hunter III's ships and planes would move 'as the eagle flies' to their destinations, smashing into friendly mine fields, mountains (in the case of planes), and beachlines.

Not really, but there is a whole lot more water to work in.

The planes still act a little goofy and have an uncanny ability to head straight for you nearly every time.

^ Also seem to have a talent for flying into land; I guess they can't fly higher than a certain "altitude" even though the land rises above that. I see survivor icons in appearing in the same places.

That does happen a lot doesnt it. I havent seen a plane pass me on a parallel course ever...

I have. At least on a few occasions, but it's a very rare event indeed. They do seem to posses radar or, in some cases, night vision.