@AxiomVerge, it's probably best not to encode game data in Spine. It may be convenient but, eg needing to edit your skeleton/animations to change the damage an enemy does probably isn't ideal. Still, we have an issue for arbitrary properties:
https://waffle.io/EsotericSoftware/spine/cards/574b9787c858761e00f3e520

We're excited about the curve editor too!

@AxiomVerge, we have always planned to allow keying X and Y separately, but seem to be continuously sidetracked with other things. You can see the task for it (and other things) here:
#26 Key X and Y translation separately
If you click the issue number there, you can subscribe for email notifications on the corresponding GitHub page. Waffle just aggregates the issues from these two GitHub trackers in a convenient view:
Editor issues
Runtime issues
As a workaround to keying X and Y separately, you could use 2 bones where one is the child of the other. You'd move one on X and the other on Y. It's certainly not as convenient though.