Uhm... Yeah, you're going to probably make the cut, and then get the job, too. If you don't want it, best thing to do is to retract your application, and simply tell them that.
I've done that TWICE in my career. Best decisions I ever made. Totally pissed off one recruiter who was yelling at me at the end of the phone call, telling me all kinds of things about my personality traits and character. Something just didn't feel right about the job, so I bailed before the last interview with the CEO of the small company. Less than a year later, my career took off in my current job. THAT felt right.
Go with your gut, man. If you're retired, picking up a science teaching job is not a "Cake-walk" position. As a former school teacher, I can tell you the three jobs in the school that I wouldn't want are #1 Principal. #2 Science Teacher. and #3 English Teacher.
The class sizes make it darn near impossible to have a life after any quiz/test/exam. You'll spend your whole freaking life grading papers, and planning lessons. Plus, as a science teacher, you'll deal a LOT with parents who complain their child (who isn't paying attention or studying) isn't doing "well" in your class.
Best comment I ever made to an irate parent on the phone when she called to ask why "is my child making a C in your class!" I responded, "Because I was generous."
It wasn't a joke, it was just a plain answer. There was a brief pause and then a totally different mom on the other end of the phone. One who was REALLY nice after that. LOL
Unless you really need that crappy paycheck, stick with substituting.
Cheers!
Skippy