The light spots on the trees is reflectivity. In the default shader that shades the leaves (inside the tree's internal network), go to the Specularity tab and decrease the reflectivity value.
About the floating trees, the settings of your population have some settings that let the population 'sit on terrain', and then a specific node to which it's connected. If you have any displacements after that node, the population will not follow those.
So make sure the last node before connecting to the planet01 is connected to the population as the 'sit on terrain'-node.