But if you want to play this game lets play.

For arguments sake lets say ECDSA is broken ... so now for every address that has ever made a transaction we can derive the private key.
So as a average crypto user; I could simple import this private key into my wallet and reindex. Voila! I now have every transaction that address every made. Good luck with your dual network or whatever you call it as simple chain analysis will reveal all!

And that is all you can say? whether it uses or not is irrelevant ... I can de-anonymize 100% of the network for all completed transactions.

I buy Darkcoins from a party that is KYC compliant, and transfer them to my wallet address A. Now the address A can be linked to me.

Next I put them through the Darksend mixing process, and now instead of having coins in address A, I have coins in addresses B1, ..., B10 for example. Then I proceed to spend the money in address B5 by sending it to a public donation address of WikiLeaks.

However, you strongly oppose WikiLeaks and everyone who supports it, and want to know who that B5 is. You import private key of the address B5, and then what?

Firstly I am not cryptography expert or ever claimed to be.

Secondly I have already answered this ... if ECDSA is cracked all your DRK funds, private keys, transactions are mine.