yea lol
 gtk or any other mapeditor can decomplie without having some problems with the map,,,, lol,,,,
 some textures r not fit or just not looks like they do in the orginal!
 and as u said lights, misc, values and other maybe wrong,,,,,
 so just try to remake it,,,,
 i just use decomplie to look how to make some stuff and/or make som perfabs of it,,,,,
 but if u r looking after perfabs then look here (
http://www.planetquake.com/bubba/)