As for DSK's possible reasons for settling, discomfort at having to answer questions about his private affairs seems an unlikely reason for settling.  DSK has been answering questions under oath about the most intimate details of his life and he has been doing so for a number of years (including dealing with sexual harassment charges while at the His sexual habits are luridly and regularly displayed in newspapers and television here and in France.  Whatever you think of him as a person, he has almost no privacy left to protect and certainly no secrets remaining worth $6 million to keep.

As I said, DSK isn't a rich man and you can't get blood from a stone.  He apparently needed to borrow his $3 million contribution to the settlement (or possibly the entire $6 million, since some news reports say that Anne Sinclair lent, rather than gifted to DSK, her $3 million share).    What possible difference would the risk of a judgement for even hundreds of millions make to a man without even $1 million?  (And whose future earnings are almost certainly sheltered from an American judgment).

Same issue about the lack of a vigorous defense.  You say settle, but I again ask why not grind.  Diallo and her lawyers present the perfect targets for grinding.  They're short on cash and manpower.  The defense can easily and inexpensively raise a large number of good constitutional and other issues that will be very difficult and costly for Diallo to defended.  Yet she must go all out on every singe one of these motions because a loss of any one would probably be fatal.

Plus, even if they win big, it's hard to see how they collect if DSK doesn't have much money in the first place and what money he does have is probably in France where it will be very, very difficult to touch (even if Diallo and her lawyers could raise enough cash on the strength of the judgment to finance such long and costly campaign).

Again, if as you surmise, he doesn't have insurance footing his bills then he's got no reason to settle.  He could have removed to federal court and ground Diallo for years upon years for a small fraction of his settlement and then,  assuming he lived long enough so that all his avenues for relatively inexpensive delays would be exhausted,  a tired and broke Diallo would probably  have settle for chump change knowing that even if she eventually tried the case to a verdict it  would take many more years before she would see so much as a single sou and quite possibly she'd never be able to collect her judgment.

Anyway, Anne Sinclair chipping some dough doesn't do much to clarify things for me. From what I gather, DSK isn't a rich man.  Presently and for the foreseeable future, he seems to have no marketable skills and severely limited earnings capacity.  What assets he does have are probably in France where they are almost certainly untouchable.  

He is also an old man with, as I say, reportedly few assets and very little capacity for ever recouping the millions supposedly paid in this settlement. If he doesn't have the $3 million or $6 million, or whatever, to lose in the first place, what's the point of going massively into debt if he doesn't have huge assets to protect?  If, however, he turns out he's rich, why not remove to federal court and turn the lawyers lose?  I have to figure that litigating the constitutional issues alone would easily burn up a lot of time and money, neither of which Diallo and her lawyers appear to have.