Can you find shinies in the ORAS demo, and also are you able to transfer them, if it isn't glalie.
I have seen some lucky guys that get shiny Pelipper, shiny Marshtomp and Grovyle in the ORAS demo. However the wild pokémons you can't caught because you don't have Pokéballs. If you can get shiny M-Glalie and M-Steelix? I search for all Google and didn't found anything BUT since you can find wild shinies and starters, I think you can find M-Glalie and M-Steelix BUT they can be shiny locked to! Don't ask me the chances but I think are the same as XY.
This demo is rather unique in that it will allow you to transfer aspects of the demo to the main Pokémon Omega Ruby & Alpha Sapphire games once purchased. This is done through the Pokémon Link feature of the games. >The demo will allow you to send over any items that you have collected throughout the playing of the demo, as well as the special Mega Evolved Pokémon that is encountered within this demo! - Serebii
If you want to check the lucky guys that found shinies:
Shiny Pelipper Shiny Grovyle Shiny Marshtomp
Hope this helps.