BSP isn't going to ever really be edited to a degree to make a full game possible using the built in functions.
I would suggest heading over to
id Sofware and grabbing the Quake SDK's working from them for BSP.
Because then ALL the data you require will be available.
As stuff suchas Lightmapping should be in the render pipeline (althought there have been a few clever reworks) you'd make a pipeline based function to first load the world itself and then add the lightmapping, then across into DBpro itself you'd make a function to read the collision data based upon the Vis which you'd also read for visible portal areas which have the arrayed vis bit data.
Lastly would be the entities affected to regions of the map.
Just a good months work on your part (about a week for a seasoned DBpro'r) and you'll have BSP which not only will load the format you want, but you can edit the format to your choosing or develop a special new format for YOUR needs.
BSP isn't as difficult as you may want to believe, especially not that prior to Quake3 and the introduction of Spline LOD Patchs and Quanternions (not how you spell it and i'm sure someone can correct it)
Using a selection of premade "BSP do this" kind of drivers really does defeat the point in the format, which was developed to be edited and adapted.
From what we've been told Patch4 is to be here in around March (so probably more likely to be Mid-April) and i can't remember if its to be the new Render Engine or just alot of updates. Eitherway alot is to be fixxed.
Anata aru kowagaru no watashi! 
