This site is very helpful for diagnosing compiler errors.
MAX_VISIBILITY_EXCEEDED
You may get this error when making a very large map, and although the obvious thing to do is to downsize the map you can do other things such as use detail brushes more so the vis data is less complicated so then the vis data wont be so large.
Also dont forget to use the caulk texture. Take into account the way the map is structurally made, it might not of given the error because the map is huge, but because its been made poorly in that you can see too much on screen at once and the view of whats on screen at once hasn’t been taken into account well enough.
Most likely, you haven’t exceeded the physical boundaries, you just made the map entirely out of structural brushes.
As for q3map2, just grab the latest version from ydnar’s site. 2.5.5-test-13 is where it’s at now.