Unarmed builds are very doable in Fallout, but the game is harder this way. The Bruiser trait isn't that great, you basically sacrifice Action Points for 2 more SPECIAL points. You can easily skip this trait and lower your Strength to 6 since you can get +3 from Power Armor and +1 from surgery. In place of Bruiser I would suggest either Small Frame or Good Natured. Small Frame lowers your max carry weight, but an unarmed character doesn't need to carry heavy weapons or ammo. Good Natured lowers your combat skills and raises some non combat, if you focus on just one combat skill then this helps a lot more than it hurts. You can easily make up the loss of your one skill while getting the benefit of the other passive skills. Unarmed weapons are Brass Knuckles, Spiked Knuckles and thr Power Fist, although hitting someone with a rock also uses the Unarmed Skill. There is is an option to get in a fist fight early in the game but otherwise there is no specific advantage to playing Unarmed only in Fallout. However there are a few fun benefits available to Unarmed characters in Fallout 2.