I wouldn't boil cider. You'll set the pectin creating permanent haze. You'll probably need pectic enzyme to clear it out. All you need to do is heat it to 170 for 20 minutes. You kill the bugs but don't set the pectin. Also, what temperature was the cider when you transferred it to the carboy and pitched your yeast? Sounds like the air space in the carboy was still pretty warm and then cooled creating a vacuum that caused the StarSan to be sucked in. If the cider was still hot when you pitched the yeast, the yeast might not be viable anymore either. I pitch yeast when the cider is in the low 60's. I put the carboy in a ice batch and keep it around 55 degrees for a sweeter flavor.