Honestly, it might make sense to simplify the gameplay a bit. Maybe in normal mode, Dennis starts with just a knife (like normal HLM), no throwing knives. Or, to make it feel more like Biker, maybe switch it to the meat cleaver. Then, in Hard Mode, you could introduce the throwing knives. That way, it removes the need for the separate throw key in either mode, the f key to throw knives thing feels like just pointless feature creep that complicates combat for no good reason.