1. You should get VHLT (V30):
http://forums.svencoop.com/showthread.php?p=488683#post488683 It's the best compilation toolset for GoldSource currently available. It has some new entities, one of them being a brush entity designed for detail brushwork, func_detail.
You can consider light fixtures like the one in your image as detail brushes. You should turn those into func_detail (see first issue). That ugly line, known as face splitting, which is caused by two solid brushes touching each other, should go away.
2. What's the initial position of that door, open or closed?