BitMillions pays out directly to your address.
So who holds their jackpot then and what does the "waiting" state imply? As long as they don't send back Bitcoins directly using a function of the network itself, they issue IOUs. Maybe for a short amount of time (in BitMillions it seems you can play for multiple rounds), maybe with a limited risk (you only risk the coins you send), maybe not even with a displayed balance but only an implicit version of it. Still, BitMillion can run right now just by refusing to pay out anything they promised to pay. I'd call that an IOU.
There's an obvious difference from changing for chips in a casino to use on the service, and keeping your balance in casino chips across the world.
True, that's why I keep a good part of my BTC in a safe place. The analogy is actually quite good, as you would likely also only want to have chips from 1 or maybe 2 casinos nearby and not some random chips from somewhere in Siberia, even if that was an honest casino over there.
What the fuck do you mean "Bitfunder currently you have to take as much debt as they give you"? They can give me 10000 BTC if they want, if they do then there's zero chance for it to be honored. My Bitfunder IOU does not randomly get exchanged for payb.tc IOUs unlike in Ripple (if I trust them both).
Whereas with Bitstamp, if they gave everyone BTC up to their trust limit, then same thing, there is zero chance for it to be honored. So in either case you just lost all your coins beyond the amount that people is willing to pay for Pirate/Bitcoin24/Bitcoinica/whatever debt (aka nothing).
I the fuck mean that the issue you are referring to (automatic exchange between 2 IOUs of the same currency where one is potentially toxic) is in my opinion a bug (in the sense of that it can't be easily adjusted in the client).
If Bitstamp did that (issue and send huge amounts of IOUs), they would be effectively bankrupt/hacked, I don't see the difference to any other service (including the ones in your signature - this exact scenario actually happend at MtGox btw.) offering fantasy amounts of balance that are not withdrawable. I would try to recover whatever is possible and then move on with my life, cutting the trust line to the bad service.
As long as I don't trust somebody not trustworthy, I have low risks. Feel free to send me any amount of your trillion BTC to my ripple address (it is in the giveaway thread), all I will receive are Bitstamp BTC that I can withdraw or XRP that I can trade.
You only repeat the risk that a gateway is hacked or goes out of order for some reason. I don't see the risk for that happening much higher than any other service in the Bitcoin universe being hacked or closing down in an unorderly fashion. This is not inherent to Ripple at all but simply the risk you cannot avoid, even dealing purely in Bitcoin (just like your BitMillion game that can still steal from you, as there is no enforcable contract in the block chain that will get you your earnings).