Blistering Tempo needs tweaking. If you already deal enough damage to exceed a creature's fire resistance, you don't actually deal any more damage until you have a check result of 10 + your damage. For example, if you deal 100 fire damage against an opponent with fire resistance 20, your damage doesn't increase above 80 until you convert more than 80 points into untyped damage (which occurs at a result of 10 + 20 + 80 = 110, or 10 + your damage). Functionally, this feat makes it so you deal your fire damage (reduced by resistances) or your Perform check -10 (reduced by resistances) to a maximum of your fire damage (ignoring resistances). This isn't necessarily a problem, it just feels very weird upon analysis.
Also, the DC is kind of irrelevant since nothing about the check cares about success or failure, only the magnitude of success. Exactly meeting the "DC" gets you exactly nothing. This shouldn't be a check with a DC.