Thanks for your feedback. The idea of annotations comes up quite a bit, and hopefully will make it in sometime soon. As for point #2, I believe there are probably a number of ways to accomplish this now (though perhaps better options on querying would help).
On an easy chart, you can set up different axes, and then assign tags to them. This will help get the scale correct for comparison. Or, you could try using the “classic chart”, where you can add multiple datasets, and they are all displayed over the top of each other. Each chart could be bound with a historical tag binding.
If I’m way off in understanding what you had in mind, please let me know!