Question 1: Cover the things you want "non impacting" with a clip brush (common/clip)
Question 2:
Theres no single answer here, as you get more advanced you will proly want to change the compile settings to fir yer map. You always compile the map in tree stages. One "meta" one "vis" and one "light". Have a look at
http://en.wikibooks.org/wiki/Q3Map2 for more info.
Compiling the light stage with -fast speeds up yer compile times *alot* but it also darkens the map somewhat, so you will have to but up the light a bit (or use -scale ~1.5 in the light compile) And you more or less always whanna use -deluxe for nexuiz maps, compiles with deluxe mapping so the map gets bump maps w/o real time lights.
I usualy do
q3map2 -meta mapname.map
q3map2 -vis mapname.map
q3map2 -light -fast -deluxe -samples 3 mapname.map
as a standard compile
-bounce means radiosity, so it will compile the light stage -bounce times +1. This can mean very very long compiles.
HOF:
<Diablo> the nex is a "game modification"
<Diablo> quake1 never had a weapon like that.
<Vordreller> there was no need for anything over 4GB untill Vista came along
<Samua>]Idea: Fix it?
<Samua>Lies, that only applies to other people.