Okay, i just had a real look at the pro maps; arachnid and Nexus, niveus and all those, and it just hit me over the head that i cannot complete a map as big as crash with my current skill in gtkradiant. So it will be put to a rest while i make some smaller maps for learning.
Edit: i am sorry i made this unnecesary topic, you may let it fall to the bottom of the list.