* A team that is being judged on scrum velocity can simply keep inflating story points to make it look like they're going faster.
* A team that is optimistic has a lower velocity. A team that is pessimistic has a higher velocity.
* If a story is 8 points that gives no clue as to whether it ought to be a 2 point (if the technical debt accrued by the team were not so high).
In practice I've found that it doesn't stabilize either. Of course that automatically means you just "weren't doing Scrum properly".
No, no, no, a thousand times no. Tracking story points by developer is the diametric opposite of "correctly following an Agile process". It gives team members, individually and collectively, an incentive to game the system, thereby corrupting your metrics and estimates. You are literally begging your team members to lie to you.
Any competent lead should be able to identify who is more and less productive without using what is essentially micromanagement by story point. Story points should only ever be tracked by team for overall velocity measurements.
Well it can, but not in a way we necessarily like - it's called the marketplace.
This is a myth. It doesn't count for that much. Programmer productivity cannot be effectively measured even by other programmers and certainly can't be measured by non-technical managers.
The fact that you are doing something can be easily verified. The fact that you are doing it effectively at an appropriate speed and quality cannot.
There's a lot more trust, salesmanship, snake oil and bullshit surrounding the development of software than most of us would like to admit.