- Knowledge. Her target was analyzed for weaknesses (like breathing) and those weaknesses were exploited.
- Motivation. In "Full Metal Jacket", Gunnery Sergeant Hartman points out what "one motivated Marine and his rifle can do". The trap was laid and sprung with precision.
- Completeness. From baiting the trap in multiple ways, to springing it, to following up, every phase of the plan was accounted for.
That said: yes, the plan was amateurish overall. But you know what? She baited the hook for two amateur heroes. She's playing at the level she's at, and knows her limits.
That was the good news. Here's some further commentary.
Fire vs. speedsters. Hurricane Hal did a very nice guest spot awhile back, and talked about the slipstream that speedsters can manipulate. Being able to ignite your whole body on fire, especially in an enclosed space, is a great counter not just against being attacked, but against someone who breathes. If necessary, Pyrepower could quickly overwhelm any oxygen-dependent speedster. But she should absolutely know beforehand if her opponent needs to breathe.
That said, you can still pit your control over fire against their control over the slipstream. If you win, they're going to painfully burn their hands if they attack you. This is a risky thing to gamble on, and you shouldn't count on it as Plan A. In this case, she didn't, but she might have.
The necessity of a custom pit trap. Digging a new trap was probably a waste of time, if a suitable candidate location could have been found. Maybe one was searched for, maybe not. Maybe digging it was just an exercise in power control. But being able to control the location of your caper - and just as importantly preventing a search of "likely locations" by the authorities - is itself a smart move.
The expendability of lairs. Pyrepower's personal lair should now be considered compromised, and I hope she fully realizes that. Any hero she takes there should be assumed to be wearing a transmitter, recorder, or similar equipment. Even if they're unconscious, or there's radio jamming in place, the technology exists to narrow down the location enough that a determined search could find it within a day or so.