Oh... I didn't mean to put the mask of shielding- or anything for that matter in the Ender Chest. It's actually located somewhere in the map.
It has protection 10, which makes it stronger than a diamond helmet.
He's there. You'll just have to run into him
Scorpio's not happening. The spider would retain its head, thus making the whole thing look awkward.
As for the fences, that's a possibility. I might experiment with changing that for the next update.
Well, here's the thing... You can go to the spawn chunk(where the canister is) and click on the command blocks with the masks on them. I'll have to double check the coords, however.
That said, the next update will include a mask forging system by which you can forge the masks for yourself, so I'd just hold off until I come out with that version.
The next update is aimed to be much more playable than the current one; all of the mask issues should be fixed and the forge system will be included. The inclusion of LoSS, skull spiders, and RoSS content should make it worthwhile too.