After looking it over in Forge I still feel like the bottom area needs to change. Especially the middle feels very separated from the rest of the map. It also feels a bit too vertical in the staircase areas. I don't know, I'm not a fan of the entire bottom part of the map. :/
I agree about the bottom center. I'm just not 100% sure what to do about that yet. And are you suggesting I lower the entire second level? That would be a huge pain in the balls. But I suppose if further testing proves it to be a problem I'll change it.
You can raise the bottom floor I guess, make it more interesting too. That would mean not having grass, though.
I'd rather keep the natural terrain. It would be cheaper better for framerate and more interesting in general.
I love the observatory. It looks so neat to me. This looks like a promising map. The only personal problem is the walk ways, just them being so thin but I bet there's a gameplay reasoning.