i spent an hour reading labels on ge silicone today at home depot (Mrs. Chipmunk was less than thrilled over this), and could not find one thing that mentioned mildew inhibitors on the label. and yes, i know, they aren't going to advertise that, but then i went over the links in the original post. this is not an amphibian issue, but a REEF TANK issue. i found this quote within the thread that was linked in the first thread.
so, after doing some research and talking to a few reefers who i know and respect a LOT, i have come to the conclusion that for a vivarium, ge silicone is indeed safe. now, if you are one of those people who wants to run an paludarium with an overkill protein skimmer in it, then i would only use aquarium sealant. also, if you are adding silicone to a waterfall, i would avoid it also, since the splashing of water somewhat duplicates a protein skimmer (but this is an extreme case).
as far as canadians and titebond 3, elmer's makes a waterproof wood glue that is almost identical to titebond 3.