No, straight lines will be fully eliminated. It will be some canyons and so on. So far we are not going to implement a maximum height as we want to create checkpoint high in the sky and low on the ground and some tunnels also...

Start positions... well... they are more like a small airfield... (not going to tell what exactly), but the should be impressive

How we create the checkpoint we still need to figure out... rings would be the simplest way, but I like things complicated