I want to be a postman

My site is driving me mental. It's like trying to solve a Rubik's Cube. Every time I get one bit sorted out, I look at another part and that's all messed up. Just when I think I've got all the green squares lined up, the red ones start misbehaving.

If my main aim is views - planting any trees immediately ruins them. I know I've got to deal with levels in my central plaza - so how do I drive a lorry across steps? If I want to lower the banks of the river, how do I stop the whole place flooding?

I've decided I want to be a postman - letter, letterbox, avoid nasty dog. Straightforward, if you know what I mean.

Aaaaagh!