As for charging cyclists? Well, they are road users too. They are also able to skip through red lights with no comeback, pay no congestion charge...etc.
And before anyone says they don't cause congestion, try driving from West to South London in the morning, it's like the bloody Tour de France
I think if people use a bike to commute on a daily basis, especially in high traffic/ built up areas, then maybe they should pay some kind of fee to do so? On the flip side of that though they are not protected by insurance. So us drivers can play skittles all day long, a granny is 50 points they literally take their life into their hands when they venture out on to the roads with nothing to back them up if you get what I mean.
I still get a cold chill when I see toddlers or small children on a bike with their parents on the road in heavy traffic areas. It's not as common now, thankfully.