@ Vilham,
Here's the official documentation in case you're unaware of it. Very good for getting familiar with SB2:
And obviously the Crymod wiki is another great resource.
@Paul,
This is indeed strange. If you look at the island level in the editor, the hill trees have sprites enabled with their 'ViewDistRatio' at '1' and the 'MaxViewDistRatio' at '2'. Those settings allow you to see them from a pretty large distance and you really shouldn't need to tweak anything else. What's the 'Config Spec' set to? Turning it to 'Very High' may solve the problem, though judging by the screens it looks like it's already at that setting.