You can do it without dedicating your new character to a specific kind of playstyle and you can do it without getting bad reputation from any faction.
Killing Benny sets you up for an easy ride for small gun users (Bennys unique gun 'Maria' is awesome) and unarmed fighters ('Love and Hate' remain useful for a very long time), but you can use this method to set you up for an easy energy weapon game too, by sneak killing all the friendly robots in REPCONN headquarters for the Q-35 matter modulator.
