Okay, I sort of Jumped the Ball on this one..

I would actually disagree with tanks not holding heat as well when was the last time you saw a coke bottle as a coffee mug? 1/4 inch glass is a better insulator than 1/16 plastic (PP at that) they also have far more flexible heating options basically ever method used in reptile keeping can be employed to heat a tank over only some for tubs. I would have concerns about the CHE at the very least make sure it is caged this may prevent a fire if it gets knocked over.

My input:

CHE + Plastic tub is dangerous but can be executed safely I guess. You need it mounted securely to a stand that can't tip over by any force that exists in your room (pets, children, wind, temp change). These things ALWAYS find a way to fall down and if it falls on plastic, you're going to have a dead pet at a minimum and a burnt down house at a maximum. I've had reptile pets for my whole life and can think of at least 5 occasions where I thought a light or heater was mounted securely and it wasn't. Luckily none of those events ended tragically. Please be careful!

I can't speak for PetSmart, but when I bought my first BP at Petco, they told me they only feed frozen once they hit the store and do not do live feedings. I don't know if this changes on a store by store basis based on what the employees are comfortable with or if they simply don't want to stock the small sized rodents they would need to feed them. I am thinking they often haven't eaten in so long because they're tossed in a separate container with a half frozen rodent and left for 15 minutes under flourescent lights in a stock room to eat it. Dark + live mouse hopper should get most snakes eating IMO.

Good luck!

@MrLang: Thanks for the concern. I have been keeping an eye on the tub and I haven't had any issues with it melting. Lamp is on the side of the tub so there are no worries of it falling & burning it. Snake took its scheduled meal with no hesitation (whoop, I'm still overly-happy about that).

@kitedemon: From the information I've read on the subject, glass aquariums are not recommended because of the heat issue and because of humidity issues. Though your point does make sense but the tub has been working perfectly for me so far, so I'm just going to keep this set up. If it ain't broke, why fix it right? lol Appreciate the insight.