How do cyclists not contribute to gridlock on city roads? normally they're the cause of it because they move so slowly more people have to stop from them and city roads tend not to have room to pass them.
If the traffic is already congested enough to cause gridlock, bikes can move as fast as, if not faster than, the cars around them. Acceleration isn't quite as good but that doesn't make much of a difference when it's just a race to pile up to the next intersection you can't clear.
As for much of the other stuff you talk about, this is really about bad cyclists rather than cycling as a mode of transport. As a cyclist who puts in effort to share the road graciously, I would love any solutions that make people better cyclists. Which is, I think, part of the point of changing stop sign laws: When you make the laws easier to follow, you're more likely to get more people willing to put in the effort to follow them. Even better if, as is the case here, the new laws have the potential to improve the situation for motorists (less time waiting for those cyclists who feel they ought to stop even though they don't have to, less uncertainty as to whether a cyclist will come to a complete stop or not).
I don't see what the point of worrying at this moment about cyclists not paying road tax. I doubt there are enough people on either side of the pond who neither drive nor take public trans to actually make a difference in the road maintenance fund. But if we get to a point where 30% of the population is exclusive cyclists, it seems likely that a lot of the tenor of the conversation will change by then, doesn't it?