convergence or not (no stable state reached - deadlocked or oscillatory) - the fact that we end up with seemingly arbitrary ordering of AS path choices really is another way of saying that we don't have a metric (e.g. path vectors are not distance vectors, unless everyone was just using shortest AS path and everything was in one single customer-provider hierarchy.
pace of convergence (and why should we need rate limits or damping?) - again, the world has operational rules which are not tidy (in this case, over time, rather than in space)...
it would certainly be nice if the clustering of network nodes/edges could be reflected in the routing and addressing, so that hierarchy and summarisation (at the IP prefix and at the AS level) would result in much smaller tables and also in less traffic (and mostly, much less dynamic traffic). But life is just not that simple in the policy world.
the damping mechanism in BGP is a simple form of a controller - for a very old article about this idea see james clerk maxwell on governors
as always xkcd has some relevant remarks
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