Translation help needed

Hello,

I just issued a part of my German pages in English:
http://www.Tourplaner-Online.de

but while translating I was sometimes in doubt of using the correct
terms. Here are som questions:

How do you express a vertical distance, is e.g. ascent or descent ok? 
Is scree the correct term for the rough boulders of a rockfall?
Is comb or ridge the right expression for a line of mountains?

THX in advantage