not a real answer to your question - but i've started to do a game-pack for gtkradiant 1.5
this editor is much better.
now to your question(s):
you are on windows, don't you? then you use qeradiant, right? sorry but i've never used this before - i'm on linux and can't help with your 1. question
the second one is: compile the map with
qbsp3 mapname.map
qrad3 mapname.bsp
there are some extra parameter available for the radiosity command - you'll see them with no parameter given in commandline.
after you compiled the map put it in base/maps-folder and start it via console: map mapname
or even start ufo with
ufo +map mapname