>>Longsword would be awkward inside, especially in a small room or hallway.<<
Depends on how you use it. You can thrust with the point of a longsword. You can also swing it like a baseball bat, rather than the wide overhead swings you see in the movies. Watch the video from Cold Steel below.
http://www.youtube.com/watch?v=2I6ulWwB99E
The Roman legions favored the short sword because they often fought in tight formations where you couldn’t just swing it around. Of course, I’m still saying a revolver is the best weapon for home defense, not a gladius.