As I said, neither me nor Satori knows what would happen. And should something happen, that's what Uicle's golems are for, and if you missed on Lucilia's demonstration, she too can quickly get involved so long as you're standing on solid ground. The demonstrations doesn't just show what you can do with your magic; it also shows what sort of power the teachers have, to encourage others to rise to their level and to put a healthy amount of fear into everyone who tries to go against them. 

It's kind of like exploding a nuclear weapon in the middle of no where; no one is suppose to be hurt, but just imagine what would happen if someone [i]does[/i]. There is of course a lot of bad ideas flowing at the time, but we'll make mistakes; where we shine is how quickly and how well we can fix them.