Ok, first and outmost, no dragging items through other solid objects

As for the balcony, sorry, but thats not possible either. For one thing, there is an invisible wall right above the arena wall, anything you throw up, hits it and bounces back. Even with the invisible wall however, that still wouldn't work. The actual arena pit and stands are 2 different cells (meaning that if you are in the pit, you can not get to the same stands without going through at least one set of doors) :Notice that when you are in the pit, there are 4 pillars, well go to the balcony and see them

. So even if you could get it past the invisible wall, the item wouldn't be up there when you got up to the balcony.
There is a way to get over the invisible wall while you are in the stands. I believe you need a high acrobatics and a certain path. Once in the arena, I'm Pretty sure you can take the fighters things, but I don't know if you can return (of course you can use the paintbrush to get you out)