I like AustinHomeBrew.com, but have bought from numerous others with little or no complaint. I like Austin's system for ordering grains, sorted by grain bill. It makes it easy to order stuff for 2 or more brew days and not have to worry about mixing things up or getting confused...well, more...
I've seen 1 story with pictures where that has happened. The laws of physics leads to water or moisture trapped inside...or some other gas as a possible explanation. Air alone will not expand enough to build the pressure needed to burst the material. It just cannot happen.
The scientific laws of temperature and pressure of a gas say that drilling holes is a waste of time. Your tubing would need to be in a molten state before there was enough internal pressure to deform it, let alone burst.
I use 6 gallon better bottles for fermenting and don't use a secondary at all. I have an IPA going right now that I dry hopped yesterday (after a week) so, I now call it "secondary" and will leave it rest for at least 2 more weeks...then I'll drop the temp and cold crash for a couple of days...
Ahh...pumpkin beers. I am curious along similar but different lines. I desire a rich, sweet, flavor packed beer...pumpkin/allspice and the like. However, I broke my right arm 5 weeks ago and haven't been able to brew anything because of my limited physical capabilities. I'm about two weeks...
From http://www.propane101.com/carbonmonoxideandpropane.htm
Properly functioning propane appliances will produce what is called an "ideal burn" during combustion and present no danger of Carbon Monoxide poisoning.
It goes on to describe in such a manner that I would not hesitate to brew in...
If you want low cost and don't mind a little DIY, search the forums for the eBay Aquarium Temperature Controller. For about $40 you can make a nice unit...less if you already have a few bits and pieces laying around.
I use this handy dandy calculator http://beerreviewdude.com/biab-calculator/ and then drain and dunk my bag a few times to provide a reasonable rinse of the grain at the end of mashing. Seems to work fine and my final wort volume has been pretty close to my target.