I have a few in mind . . .

Where is everyone thinking of starting?

We'll have everyone/ mostly everyone be all together, and as we get other members in we can fan out a bit more?

It will be good to have everyone (mains) together before spitting up.
I was also thinking that Chaos Control might happen - we all get separated as more people join into different areas.

It will be good to have someone do something bad to send everyone away into those different areas. (Mephiles, this might be you?)
Just a thought!

ALSO
For the Chaos Emeralds, I have an idea!
I have all seven emeralds in single pictures for each color. Every 20-50 posts (or a dice roll) someone will find an Emerald.
I will PM them the image they can put up with there post. (It can be in a spoiler, up to you.)
That way we know whos got what emerald. It's not going to be fast to find them, nor slow. I guess luck?
Also being fair on everyone to have a chance. But might do this when we have more people.