As I said, 3rd map, you're going to overtake Chinny and I. That's the whole point and I'll be happy to see it. As I said, 2006 and 2007 not many people made many maps, except myself. I made 40-70 by that point and was experimenting a lot with different types of map, so alot of the maps seem less in quality than today's maps. Thing is, players don't see maps in the same way as mappers do. Mappers tend to judge a map via SDK rather than seeing how the player enjoys it. Which is why you can not please everyone in one map ever and why servers will host at least 2 or 3 of the default maps.
There's your BSP error. Congratulations on the smallest BSP error I've ever seen. The BSP is not the problem, it's the bug.
Now I'm pretty sure, you don't need to move the whole scaffolding, but only the edge of the diagonal support that in 2D view, is seemingly not quite where it needs to be.
Also I notice something blue near the pink lol... try making the floor semi, it might work. but first I would move the diagonal support a little, up vertically or closer to the 16 grid line.