well, when a I say warranty, I mean that if it should come DOA I doubt you would have any trouble getting it replaced.

Hobbypartz did replace a GT3b radio for me without any issues tho. They are better than buying direct from china via ebay.

I am not sure that lipos on a plane (even at altitude) are an issue. I would think if anything, low temps would help prevent them for rupturing a cell.

RC planes and helis having lipos catching on fire often has to do with a lipo that is not up to the task (a 20c lipo when you should have used a 30 or 40c pack)
Poor quality cells can become unbalanced, but any time that has happened to my packs there is not enough juice left in them to cause a fire.
Ive had a pack go bad (3s, 1 dead cell) were the good cells only had 3v. beat it with a bat....did see a puff of smoke and that was it. A lipo has to have a decent amount of charge and be either stressed (overdrawn or overcharged) or punctured in order to get the fire.

I have heard of NIMH cells catching fire too. And even a decent NIMH pack can get fairly hot at the end of a race or bash session.

woops, off topic