So we want a universal currency that can be used world wide (instead of Euro/USD/EGP/RR...etc) so it wouldn't make sense to make the coin pegged to them. Right now, I'm thinking that it maybe can be stable based on the "checking account" coin and what makes it stable is you can redeem these stable coins to the checking coin and exchange it for anything else (USD lets say) so people will be enforcing this stability as it can be redeemed.
Assuming what I understood about this post is correct, I still think in the end it won't be stable anymore. Even if the value is pegged to those checking coins, eventually the value of those things will be determined by USD/any other fiat currency. It's just making the process a bit longer, and I think it isn't effective and efficient.
I'll respond to your other points later if I have the time.