While I don't quite agree with your weapon analogy, I completely agree that charging based on potential harm is much more smart. It would be silly to charge drivers, cyclists, bus drivers, and pilots all the same for the same issues.
And, yes, cyclist who also commit acts of criminal negligence endangering the life, health, and property of others should also be held accountable in direct proportion to how substantial of a weapon they use. Two ton GVW moving at 60mph vs. 200 pound GVW moving at 25mph both carry potentially dangerous energy if they for example plow into a pedestrian legally crossing with ROW in a crosswalk. One packs a whole lot more dangerous energy then the other but never the less they both can be dangerous if mis-used just to different extents.