Considering that one of the only threads I've made is of the various pieces of artwork that I've made for Toontown Rewritten,
I would have to say yes, I do indeed work in part for the TTR project ;)
It very well may work out; I'm just saying I can't see it lasting very long.
I don't know much about SFS -- I only googled it, but successful MMOs are coded in more traditional languages. Plus, many consider Flash to be outdated and dead.
What (server-side) languages do you and your developers know? Any C, C++, or C#? What other languages would you plan on this game being coded in? I can't see it working if it was simply in Flash. Even Nick (from OVMK) coded the original in JS, HTML5, and Flash.