Nice, it's great how the game just grabs you and you keep building on something simple...
What is the inside like ? most people never seem to do the inside of the buildings. - Just wondering.
Your park is big enough, so that those tower rides don't look out of place. [up]
Maybe vary the height of the trees (sink a few down), and fill in randomly some more so that they don't look evenly spaced during an aerial view. At the lower level views it all looks great as it is right now. [cool]
You can delete the trees without waiting for the update - simply select them and press delete.