I honestly don't know about the heat. It's just something I wouldn't do. Guys siphon gas with a hose, I'm not lining up for that one either. There are lots of things we "can" do, and I'm really into the, "hey Bubba watch this" moments. I just try and avoid anything that can't be fixed with stitches or a cast.
As far as the bottles go, I wish I could provide a comprehensive list, but I know you are okay with LDPE, HDPE, and want to stay away from other PVC (or at least test it well) and poly styrene.
What happens if there is an adverse effect is the other plastic which is harder will start to absorb the plasticizer. This will make it soft and ultimately compromise it's integrity. I'm not sure about it contaminating your plastic, but my gut is it would have some less than desirable effect?

Jason