Yeah, the so called "well established bankrupcy procedure" is always possible.
There is a reason why bankruptcy procedures are well established and proven practice.
I have a different opinion on this. If it is a case where the reason for bankruptcy is illiquidity while there are a lot of (valuable)assests behind that could be monetarized it might make sense. In this case you have basically the website plus some minimal private savings which would be eaten up by the costs of the liquidation procedure. I also dont think that selling the website would bring so much. It is just another buerocratic process where in the end no one would get anything except the lawyers.
I was also considering this option for my frozen coins, since it is the "official standard procedure", but out of my frozen 620 coins I would get back maybe 50 after one year
You don't have "frozen" coins for there are no coins at all. In this case "frozen" is just an oxymoron for missing! You can get some coins only if bitmarket.eu makes profit in the future.
I agree, the term does not matter, the coins are simply not there anymore.
one would need the admins support to learn how the site works
So, you are ready to live with the constant extortion of shutting up this website and losing your "frozen" coins?
No, there should be a clear way out with a restoration plan (reopening the website, sharing profits between users etc etc.) which cannot be changed anymore once everyone participating "formally" agreed on it.
I (personally) am also not willing to bid for an auction for the website in case of liqudation
The liquidation in a bankruptcy procedure doesn't mean that this website will be liquidated. Liquidation means that creditors will get best possible price for the service and that current owner will be held responsible including criminal charges! Only then you can be confident that current owner made their best efforts to compensate creditors!
The liquidation in fact would mean that the website closes entirely and legally it is part of the liquidation mass as it might have some value. And in this case the current owner would do a shit in doing any extra effort to pay back additional user funds beyond what is left over after liquidation.