Welcome to the playground! The concept is solid, and the name is spot on.
I'm not a huge fan of using "uses of a stance" as a transferable resource like superiority dice or whatever. It's clumsy and doesn't really make sense.
I would:
- Make Misstep always-on (so it doesn't have limited uses or require a bonus action).
- Get rid of the extra reaction. Mainly because it feels wrong.
- Make Strength of Spirit straight-up once per short rest.
- Package the Dance... into the Misstep, so the whole thing costs one reaction.
- Change Salamander's Spite into an actual, cone-shaped breath weapon, like the dragonborn's (with the numbers re-balanced as appropriate)