>>- Break Glass
This might be a possibility... If you're concerned about this, you might want to swap the plate glass included with a normal Vision cage for tempered glass (though I'm not entirely certain that would help). Or, see if it would be possible to place a slightly thicker piece of glass in the tracks.
>>- Break Glass Track
>>- Lift Glass out of Track and Push Out Glass
I wouldn't spend much time worrying about either of these possibilities. The track on my Visions is aluminum and seems unlikely to break. I have a difficult time getting the glass out of the tracks myself, so I think it unlikely a snake could do it. Unless your glass is really loose for some reason?
>>- Break Showcase Lock
If your locks are like mine and you use them correctly, I don't think this is possible. My locks are the standard type you see used with sliding by-pass doors: there's a U-shaped piece of metal with one side of the 'U' longer than the other. The long side is located between the glass doors and you slide the lock cylinder onto it.
>>Has anyone ever had an escape by these (or any other) means?
I haven't ever had anyone escape from one of my Vision cages... though I don't keep anything nearly as big as a Burm!