You might have had an issue before where you want to rotate something to a specific position, but it just won't go where you want. Try doing this
In your editor > Options > Preferences > Editor > Rotation Grid > RotGridSize
Set that to 256 or any value lower than the standard, which is 1024. You should be able to rotate much more freely, without turning off the Rotation Grid, if you turn it off you get many bsp holes.
Included a picture as well
